use chrono::Datelike; use crate::{ calc_result::CalcResult, constants::{LAST_COLUMN, LAST_ROW, MAXIMUM_DATE_SERIAL_NUMBER, MINIMUM_DATE_SERIAL_NUMBER}, expressions::{parser::Node, token::Error, types::CellReferenceIndex}, formatter::dates::from_excel_date, model::Model, }; use super::financial_util::{compute_irr, compute_npv, compute_rate, compute_xirr, compute_xnpv}; // See: // https://github.com/apache/openoffice/blob/c014b5f2b55cff8d4b0c952d5c16d62ecde09ca1/main/scaddins/source/analysis/financial.cxx fn is_less_than_one_year(start_date: i64, end_date: i64) -> Result { let end = from_excel_date(end_date)?; let start = from_excel_date(start_date)?; if end_date - start_date < 365 { return Ok(true); } let end_year = end.year(); let start_year = start.year(); if end_year == start_year { return Ok(true); } if end_year != start_year + 1 { return Ok(false); } let start_month = start.month(); let end_month = end.month(); if end_month < start_month { return Ok(true); } if end_month > start_month { return Ok(false); } // we are one year later same month let start_day = start.day(); let end_day = end.day(); Ok(end_day <= start_day) } fn compute_payment( rate: f64, nper: f64, pv: f64, fv: f64, period_start: bool, ) -> Result { if rate == 0.0 { if nper == 0.0 { return Err((Error::NUM, "Period count must be non zero".to_string())); } return Ok(-(pv + fv) / nper); } if rate <= -1.0 { return Err((Error::NUM, "Rate must be > -1".to_string())); }; let rate_nper = if nper == 0.0 { 1.0 } else { (1.0 + rate).powf(nper) }; let result = if period_start { // type = 1 (fv + pv * rate_nper) * rate / ((1.0 + rate) * (1.0 - rate_nper)) } else { (fv * rate + pv * rate * rate_nper) / (1.0 - rate_nper) }; if result.is_nan() || result.is_infinite() { return Err((Error::NUM, "Invalid result".to_string())); } Ok(result) } fn compute_future_value( rate: f64, nper: f64, pmt: f64, pv: f64, period_start: bool, ) -> Result { if rate == 0.0 { return Ok(-pv - pmt * nper); } if rate == -1.0 && nper < 0.0 { return Err((Error::DIV, "Divide by zero".to_string())); } let rate_nper = (1.0 + rate).powf(nper); let fv = if period_start { // type = 1 -pv * rate_nper - pmt * (1.0 + rate) * (rate_nper - 1.0) / rate } else { -pv * rate_nper - pmt * (rate_nper - 1.0) / rate }; if fv.is_nan() { return Err((Error::NUM, "Invalid result".to_string())); } if !fv.is_finite() { return Err((Error::DIV, "Divide by zero".to_string())); } Ok(fv) } fn compute_ipmt( rate: f64, period: f64, period_count: f64, present_value: f64, future_value: f64, period_start: bool, ) -> Result { // http://www.staff.city.ac.uk/o.s.kerr/CompMaths/WSheet4.pdf // https://www.experts-exchange.com/articles/1948/A-Guide-to-the-PMT-FV-IPMT-and-PPMT-Functions.html // type = 0 (end of period) // impt = -[(1+rate)^(period-1)*(pv*rate+pmt)-pmt] // ipmt = FV(rate, period-1, payment, pv, type) * rate // type = 1 (beginning of period) // ipmt = (FV(rate, period-2, payment, pv, type) - payment) * rate let payment = compute_payment( rate, period_count, present_value, future_value, period_start, )?; if period < 1.0 || period >= period_count + 1.0 { return Err(( Error::NUM, format!("Period must be between 1 and {}", period_count + 1.0), )); } if period == 1.0 && period_start { Ok(0.0) } else { let p = if period_start { period - 2.0 } else { period - 1.0 }; let c = if period_start { -payment } else { 0.0 }; let fv = compute_future_value(rate, p, payment, present_value, period_start)?; Ok((fv + c) * rate) } } fn compute_ppmt( rate: f64, period: f64, period_count: f64, present_value: f64, future_value: f64, period_start: bool, ) -> Result { let payment = compute_payment( rate, period_count, present_value, future_value, period_start, )?; // It's a bit unfortunate that the first thing compute_ipmt does is compute_payment again let ipmt = compute_ipmt( rate, period, period_count, present_value, future_value, period_start, )?; Ok(payment - ipmt) } // These formulas revolve around compound interest and annuities. // The financial functions pv, rate, nper, pmt and fv: // rate = interest rate per period // nper (number of periods) = loan term // pv (present value) = loan amount // fv (future value) = cash balance after last payment. Default is 0 // type = the annuity type indicates when payments are due // * 0 (default) Payments are made at the end of the period // * 1 Payments are made at the beginning of the period (like a lease or rent) // The variable period_start is true if type is 1 // They are linked by the formulas: // If rate != 0 // $pv*(1+rate)^nper+pmt*(1+rate*type)*((1+rate)^nper-1)/rate+fv=0$ // If rate = 0 // $pmt*nper+pv+fv=0$ // All, except for rate are easily solvable in terms of the others. // In these formulas the payment (pmt) is normally negative impl Model { fn get_array_of_numbers_generic( &mut self, arg: &Node, cell: &CellReferenceIndex, accept_number_node: bool, handle_empty_cell: impl Fn() -> Result, CalcResult>, handle_non_number_cell: impl Fn() -> Result, CalcResult>, ) -> Result, CalcResult> { let mut values = Vec::new(); match self.evaluate_node_in_context(arg, *cell) { CalcResult::Number(value) if accept_number_node => values.push(value), CalcResult::Number(_) => { return Err(CalcResult::new_error( Error::VALUE, *cell, "Expected range of numbers".to_string(), )); } CalcResult::Range { left, right } => { if left.sheet != right.sheet { return Err(CalcResult::new_error( Error::VALUE, *cell, "Ranges are in different sheets".to_string(), )); } let sheet = left.sheet; let row1 = left.row; let mut row2 = right.row; let column1 = left.column; let mut column2 = right.column; if row1 == 1 && row2 == LAST_ROW { row2 = self .workbook .worksheet(sheet) .map_err(|_| { CalcResult::new_error( Error::ERROR, *cell, format!("Invalid worksheet index: '{}'", sheet), ) })? .dimension() .max_row; } if column1 == 1 && column2 == LAST_COLUMN { column2 = self .workbook .worksheet(sheet) .map_err(|_| { CalcResult::new_error( Error::ERROR, *cell, format!("Invalid worksheet index: '{}'", sheet), ) })? .dimension() .max_column; } for row in row1..=row2 { for column in column1..=column2 { let cell_ref = CellReferenceIndex { sheet, row, column }; match self.evaluate_cell(cell_ref) { CalcResult::Number(value) => values.push(value), error @ CalcResult::Error { .. } => return Err(error), CalcResult::EmptyCell => { if let Some(value) = handle_empty_cell()? { values.push(value); } } _ => { if let Some(value) = handle_non_number_cell()? { values.push(value); } } } } } } error @ CalcResult::Error { .. } => return Err(error), _ => { handle_non_number_cell()?; } } Ok(values) } fn get_array_of_numbers( &mut self, arg: &Node, cell: &CellReferenceIndex, ) -> Result, CalcResult> { self.get_array_of_numbers_generic( arg, cell, true, // accept_number_node || Ok(None), // Ignore empty cells || Ok(None), // Ignore non-number cells ) } fn get_array_of_numbers_xpnv( &mut self, arg: &Node, cell: &CellReferenceIndex, error: Error, ) -> Result, CalcResult> { self.get_array_of_numbers_generic( arg, cell, true, // accept_number_node || { Err(CalcResult::new_error( Error::NUM, *cell, "Expected number".to_string(), )) }, || { Err(CalcResult::new_error( error.clone(), *cell, "Expected number".to_string(), )) }, ) } fn get_array_of_numbers_xirr( &mut self, arg: &Node, cell: &CellReferenceIndex, ) -> Result, CalcResult> { self.get_array_of_numbers_generic( arg, cell, false, // Do not accept a single number node || Ok(Some(0.0)), // Treat empty cells as zero || { Err(CalcResult::new_error( Error::VALUE, *cell, "Expected number".to_string(), )) }, ) } /// PMT(rate, nper, pv, [fv], [type]) pub(crate) fn fn_pmt(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(3..=5).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; // number of periods let nper = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; // present value let pv = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; // future_value let fv = if arg_count > 3 { match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.0 }; let period_start = if arg_count > 4 { match self.get_number(&args[4], cell) { Ok(f) => f != 0.0, Err(s) => return s, } } else { // at the end of the period false }; match compute_payment(rate, nper, pv, fv, period_start) { Ok(p) => CalcResult::Number(p), Err(error) => CalcResult::Error { error: error.0, origin: cell, message: error.1, }, } } // PV(rate, nper, pmt, [fv], [type]) pub(crate) fn fn_pv(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(3..=5).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; // nper let period_count = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; // pmt let payment = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; // fv let future_value = if arg_count > 3 { match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.0 }; let period_start = if arg_count > 4 { match self.get_number(&args[4], cell) { Ok(f) => f != 0.0, Err(s) => return s, } } else { // at the end of the period false }; if rate == 0.0 { return CalcResult::Number(-future_value - payment * period_count); } if rate == -1.0 { return CalcResult::Error { error: Error::DIV, origin: cell, message: "Rate must be != -1".to_string(), }; }; let rate_nper = (1.0 + rate).powf(period_count); let result = if period_start { // type = 1 -(future_value * rate + payment * (1.0 + rate) * (rate_nper - 1.0)) / (rate * rate_nper) } else { (-future_value * rate - payment * (rate_nper - 1.0)) / (rate * rate_nper) }; if result.is_nan() || result.is_infinite() { return CalcResult::Error { error: Error::NUM, origin: cell, message: "Invalid result".to_string(), }; } CalcResult::Number(result) } // RATE(nper, pmt, pv, [fv], [type], [guess]) pub(crate) fn fn_rate(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(3..=5).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let nper = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let pmt = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let pv = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; // fv let fv = if arg_count > 3 { match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.0 }; let annuity_type = if arg_count > 4 { match self.get_number(&args[4], cell) { Ok(f) => i32::from(f != 0.0), Err(s) => return s, } } else { // at the end of the period 0 }; let guess = if arg_count > 5 { match self.get_number(&args[5], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.1 }; match compute_rate(pv, fv, nper, pmt, annuity_type, guess) { Ok(f) => CalcResult::Number(f), Err(error) => CalcResult::Error { error: error.0, origin: cell, message: error.1, }, } } // NPER(rate,pmt,pv,[fv],[type]) pub(crate) fn fn_nper(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(3..=5).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; // pmt let payment = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; // pv let present_value = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; // fv let future_value = if arg_count > 3 { match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.0 }; let period_start = if arg_count > 4 { match self.get_number(&args[4], cell) { Ok(f) => f != 0.0, Err(s) => return s, } } else { // at the end of the period false }; if rate == 0.0 { if payment == 0.0 { return CalcResult::Error { error: Error::DIV, origin: cell, message: "Divide by zero".to_string(), }; } return CalcResult::Number(-(future_value + present_value) / payment); } if rate < -1.0 { return CalcResult::Error { error: Error::NUM, origin: cell, message: "Rate must be > -1".to_string(), }; }; let rate_nper = if period_start { // type = 1 if payment != 0.0 { let term = payment * (1.0 + rate) / rate; (1.0 - future_value / term) / (1.0 + present_value / term) } else { -future_value / present_value } } else { // type = 0 if payment != 0.0 { let term = payment / rate; (1.0 - future_value / term) / (1.0 + present_value / term) } else { -future_value / present_value } }; if rate_nper <= 0.0 { return CalcResult::Error { error: Error::NUM, origin: cell, message: "Cannot compute.".to_string(), }; } let result = rate_nper.ln() / (1.0 + rate).ln(); CalcResult::Number(result) } // FV(rate, nper, pmt, [pv], [type]) pub(crate) fn fn_fv(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(3..=5).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; // number of periods let nper = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; // payment let pmt = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; // present value let pv = if arg_count > 3 { match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.0 }; let period_start = if arg_count > 4 { match self.get_number(&args[4], cell) { Ok(f) => f != 0.0, Err(s) => return s, } } else { // at the end of the period false }; match compute_future_value(rate, nper, pmt, pv, period_start) { Ok(f) => CalcResult::Number(f), Err(error) => CalcResult::Error { error: error.0, origin: cell, message: error.1, }, } } // IPMT(rate, per, nper, pv, [fv], [type]) pub(crate) fn fn_ipmt(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(4..=6).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; // per let period = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; // nper let period_count = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; // pv let present_value = match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, }; // fv let future_value = if arg_count > 4 { match self.get_number(&args[4], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.0 }; let period_start = if arg_count > 5 { match self.get_number(&args[5], cell) { Ok(f) => f != 0.0, Err(s) => return s, } } else { // at the end of the period false }; let ipmt = match compute_ipmt( rate, period, period_count, present_value, future_value, period_start, ) { Ok(f) => f, Err(error) => { return CalcResult::Error { error: error.0, origin: cell, message: error.1, } } }; CalcResult::Number(ipmt) } // PPMT(rate, per, nper, pv, [fv], [type]) pub(crate) fn fn_ppmt(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(4..=6).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; // per let period = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; // nper let period_count = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; // pv let present_value = match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, }; // fv let future_value = if arg_count > 4 { match self.get_number(&args[4], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.0 }; let period_start = if arg_count > 5 { match self.get_number(&args[5], cell) { Ok(f) => f != 0.0, Err(s) => return s, } } else { // at the end of the period false }; let ppmt = match compute_ppmt( rate, period, period_count, present_value, future_value, period_start, ) { Ok(f) => f, Err(error) => { return CalcResult::Error { error: error.0, origin: cell, message: error.1, } } }; CalcResult::Number(ppmt) } // NPV(rate, value1, [value2],...) // npv = Sum[value[i]/(1+rate)^i, {i, 1, n}] pub(crate) fn fn_npv(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if arg_count < 2 { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let mut values = Vec::new(); for arg in &args[1..] { match self.evaluate_node_in_context(arg, cell) { CalcResult::Number(value) => values.push(value), CalcResult::Range { left, right } => { if left.sheet != right.sheet { return CalcResult::new_error( Error::VALUE, cell, "Ranges are in different sheets".to_string(), ); } let row1 = left.row; let mut row2 = right.row; let column1 = left.column; let mut column2 = right.column; if row1 == 1 && row2 == LAST_ROW { row2 = match self.workbook.worksheet(left.sheet) { Ok(s) => s.dimension().max_row, Err(_) => { return CalcResult::new_error( Error::ERROR, cell, format!("Invalid worksheet index: '{}'", left.sheet), ); } }; } if column1 == 1 && column2 == LAST_COLUMN { column2 = match self.workbook.worksheet(left.sheet) { Ok(s) => s.dimension().max_column, Err(_) => { return CalcResult::new_error( Error::ERROR, cell, format!("Invalid worksheet index: '{}'", left.sheet), ); } }; } for row in row1..row2 + 1 { for column in column1..(column2 + 1) { match self.evaluate_cell(CellReferenceIndex { sheet: left.sheet, row, column, }) { CalcResult::Number(value) => { values.push(value); } error @ CalcResult::Error { .. } => return error, _ => { // We ignore booleans and strings } } } } } error @ CalcResult::Error { .. } => return error, _ => { // We ignore booleans and strings } }; } match compute_npv(rate, &values) { Ok(f) => CalcResult::Number(f), Err(error) => CalcResult::new_error(error.0, cell, error.1), } } // Returns the internal rate of return for a series of cash flows represented by the numbers // in values. // These cash flows do not have to be even, as they would be for an annuity. // However, the cash flows must occur at regular intervals, such as monthly or annually. // The internal rate of return is the interest rate received for an investment consisting // of payments (negative values) and income (positive values) that occur at regular periods // IRR(values, [guess]) pub(crate) fn fn_irr(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if arg_count > 2 || arg_count == 0 { return CalcResult::new_args_number_error(cell); } let values = match self.get_array_of_numbers(&args[0], &cell) { Ok(s) => s, Err(error) => return error, }; let guess = if arg_count == 2 { match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.1 }; match compute_irr(&values, guess) { Ok(f) => CalcResult::Number(f), Err(error) => CalcResult::Error { error: error.0, origin: cell, message: error.1, }, } } // XNPV(rate, values, dates) pub(crate) fn fn_xnpv(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(2..=3).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let values = match self.get_array_of_numbers_xpnv(&args[1], &cell, Error::NUM) { Ok(s) => s, Err(error) => return error, }; let dates = match self.get_array_of_numbers_xpnv(&args[2], &cell, Error::VALUE) { Ok(s) => s, Err(error) => return error, }; // Decimal points on dates are truncated let dates: Vec = dates.iter().map(|s| s.floor()).collect(); let values_count = values.len(); // If values and dates contain a different number of values, XNPV returns the #NUM! error value. if values_count != dates.len() { return CalcResult::new_error( Error::NUM, cell, "Values and dates must be the same length".to_string(), ); } if values_count == 0 { return CalcResult::new_error(Error::NUM, cell, "Not enough values".to_string()); } let first_date = dates[0]; for date in &dates { if *date < MINIMUM_DATE_SERIAL_NUMBER as f64 || *date > MAXIMUM_DATE_SERIAL_NUMBER as f64 { // Excel docs claim that if any number in dates is not a valid date, // XNPV returns the #VALUE! error value, but it seems to return #VALUE! return CalcResult::new_error( Error::NUM, cell, "Invalid number for date".to_string(), ); } // If any number in dates precedes the starting date, XNPV returns the #NUM! error value. if date < &first_date { return CalcResult::new_error( Error::NUM, cell, "Date precedes the starting date".to_string(), ); } } // It seems Excel returns #NUM! if rate < 0, this is only necessary if r <= -1 if rate <= 0.0 { return CalcResult::new_error(Error::NUM, cell, "rate needs to be > 0".to_string()); } match compute_xnpv(rate, &values, &dates) { Ok(f) => CalcResult::Number(f), Err((error, message)) => CalcResult::new_error(error, cell, message), } } // XIRR(values, dates, [guess]) pub(crate) fn fn_xirr(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(2..=3).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let values = match self.get_array_of_numbers_xirr(&args[0], &cell) { Ok(s) => s, Err(error) => return error, }; let dates = match self.get_array_of_numbers_xirr(&args[1], &cell) { Ok(s) => s, Err(error) => return error, }; let guess = if arg_count == 3 { match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, } } else { 0.1 }; // Decimal points on dates are truncated let dates: Vec = dates.iter().map(|s| s.floor()).collect(); let values_count = values.len(); // If values and dates contain a different number of values, XNPV returns the #NUM! error value. if values_count != dates.len() { return CalcResult::new_error( Error::NUM, cell, "Values and dates must be the same length".to_string(), ); } if values_count == 0 { return CalcResult::new_error(Error::NUM, cell, "Not enough values".to_string()); } let first_date = dates[0]; for date in &dates { if *date < MINIMUM_DATE_SERIAL_NUMBER as f64 || *date > MAXIMUM_DATE_SERIAL_NUMBER as f64 { return CalcResult::new_error( Error::NUM, cell, "Invalid number for date".to_string(), ); } // If any number in dates precedes the starting date, XIRR returns the #NUM! error value. if date < &first_date { return CalcResult::new_error( Error::NUM, cell, "Date precedes the starting date".to_string(), ); } } match compute_xirr(&values, &dates, guess) { Ok(f) => CalcResult::Number(f), Err((error, message)) => CalcResult::Error { error, origin: cell, message, }, } } // MIRR(values, finance_rate, reinvest_rate) // The formula is: // $$ (-NPV(r1, v_p) * (1+r1)^y)/(NPV(r2, v_n)*(1+r2))^(1/y)-1$$ // where: // $r1$ is the reinvest_rate, $r2$ the finance_rate // $v_p$ the vector of positive values // $v_n$ the vector of negative values // and $y$ is dimension of $v$ - 1 (number of years) pub(crate) fn fn_mirr(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 3 { return CalcResult::new_args_number_error(cell); } let values = match self.get_array_of_numbers(&args[0], &cell) { Ok(s) => s, Err(error) => return error, }; let finance_rate = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let reinvest_rate = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let mut positive_values = Vec::new(); let mut negative_values = Vec::new(); let mut last_negative_index = -1; for (index, &value) in values.iter().enumerate() { let (p, n) = if value >= 0.0 { (value, 0.0) } else { last_negative_index = index as i32; (0.0, value) }; positive_values.push(p); negative_values.push(n); } if last_negative_index == -1 { return CalcResult::new_error( Error::DIV, cell, "Invalid data for MIRR function".to_string(), ); } // We do a bit of analysis if the rates are -1 as there are some cancellations // It is probably not important. let years = values.len() as f64; let top = if reinvest_rate == -1.0 { // This is finite match positive_values.last() { Some(f) => *f, None => 0.0, } } else { match compute_npv(reinvest_rate, &positive_values) { Ok(npv) => -npv * ((1.0 + reinvest_rate).powf(years)), Err((error, message)) => { return CalcResult::Error { error, origin: cell, message, } } } }; let bottom = if finance_rate == -1.0 { if last_negative_index == 0 { // This is still finite negative_values[last_negative_index as usize] } else { // or -Infinity depending of the sign in the last_negative_index coef. // But it is irrelevant for the calculation f64::INFINITY } } else { match compute_npv(finance_rate, &negative_values) { Ok(npv) => npv * (1.0 + finance_rate), Err((error, message)) => { return CalcResult::Error { error, origin: cell, message, } } } }; let result = (top / bottom).powf(1.0 / (years - 1.0)) - 1.0; if result.is_infinite() { return CalcResult::new_error(Error::DIV, cell, "Division by 0".to_string()); } if result.is_nan() { return CalcResult::new_error(Error::NUM, cell, "Invalid data for MIRR".to_string()); } CalcResult::Number(result) } // ISPMT(rate, per, nper, pv) // Formula is: // $$pv*rate*\left(\frac{per}{nper}-1\right)$$ pub(crate) fn fn_ispmt(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 4 { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let per = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let nper = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let pv = match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, }; if nper == 0.0 { return CalcResult::new_error(Error::DIV, cell, "Division by 0".to_string()); } CalcResult::Number(pv * rate * (per / nper - 1.0)) } // RRI(nper, pv, fv) // Formula is // $$ \left(\frac{fv}{pv}\right)^{\frac{1}{nper}}-1 $$ pub(crate) fn fn_rri(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 3 { return CalcResult::new_args_number_error(cell); } let nper = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let pv = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let fv = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; if nper <= 0.0 { return CalcResult::new_error(Error::NUM, cell, "nper should be >0".to_string()); } if pv == 0.0 { // Note error is NUM not DIV/0 also bellow return CalcResult::new_error(Error::NUM, cell, "Division by 0".to_string()); } let result = (fv / pv).powf(1.0 / nper) - 1.0; if result.is_infinite() { return CalcResult::new_error(Error::NUM, cell, "Division by 0".to_string()); } if result.is_nan() { return CalcResult::new_error(Error::NUM, cell, "Invalid data for RRI".to_string()); } CalcResult::Number(result) } // SLN(cost, salvage, life) // Formula is: // $$ \frac{cost-salvage}{life} $$ pub(crate) fn fn_sln(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 3 { return CalcResult::new_args_number_error(cell); } let cost = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let salvage = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let life = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; if life == 0.0 { return CalcResult::new_error(Error::DIV, cell, "Division by 0".to_string()); } let result = (cost - salvage) / life; CalcResult::Number(result) } // SYD(cost, salvage, life, per) // Formula is: // $$ \frac{(cost-salvage)*(life-per+1)*2}{life*(life+1)} $$ pub(crate) fn fn_syd(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 4 { return CalcResult::new_args_number_error(cell); } let cost = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let salvage = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let life = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let per = match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, }; if life == 0.0 { return CalcResult::new_error(Error::NUM, cell, "Division by 0".to_string()); } if per > life || per <= 0.0 { return CalcResult::new_error(Error::NUM, cell, "per should be <= life".to_string()); } let result = ((cost - salvage) * (life - per + 1.0) * 2.0) / (life * (life + 1.0)); CalcResult::Number(result) } // NOMINAL(effective_rate, npery) // Formula is: // $$ n\times\left(\left(1+r\right)^{\frac{1}{n}}-1\right) $$ // where: // $r$ is the effective interest rate // $n$ is the number of periods per year pub(crate) fn fn_nominal(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 2 { return CalcResult::new_args_number_error(cell); } let effect_rate = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let npery = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f.floor(), Err(s) => return s, }; if effect_rate <= 0.0 || npery < 1.0 { return CalcResult::new_error(Error::NUM, cell, "Invalid arguments".to_string()); } let result = ((1.0 + effect_rate).powf(1.0 / npery) - 1.0) * npery; if result.is_infinite() { return CalcResult::new_error(Error::DIV, cell, "Division by 0".to_string()); } if result.is_nan() { return CalcResult::new_error(Error::NUM, cell, "Invalid data for RRI".to_string()); } CalcResult::Number(result) } // EFFECT(nominal_rate, npery) // Formula is: // $$ \left(1+\frac{r}{n}\right)^n-1 $$ // where: // $r$ is the nominal interest rate // $n$ is the number of periods per year pub(crate) fn fn_effect(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 2 { return CalcResult::new_args_number_error(cell); } let nominal_rate = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let npery = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f.floor(), Err(s) => return s, }; if nominal_rate <= 0.0 || npery < 1.0 { return CalcResult::new_error(Error::NUM, cell, "Invalid arguments".to_string()); } let result = (1.0 + nominal_rate / npery).powf(npery) - 1.0; if result.is_infinite() { return CalcResult::new_error(Error::DIV, cell, "Division by 0".to_string()); } if result.is_nan() { return CalcResult::new_error(Error::NUM, cell, "Invalid data for RRI".to_string()); } CalcResult::Number(result) } // PDURATION(rate, pv, fv) // Formula is: // $$ \frac{log(fv) - log(pv)}{log(1+r)} $$ // where: // * $r$ is the interest rate per period // * $pv$ is the present value of the investment // * $fv$ is the desired future value of the investment pub(crate) fn fn_pduration(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 3 { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let pv = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let fv = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; if fv <= 0.0 || pv <= 0.0 || rate <= 0.0 { return CalcResult::new_error(Error::NUM, cell, "Invalid arguments".to_string()); } let result = (fv.ln() - pv.ln()) / ((1.0 + rate).ln()); if result.is_infinite() { return CalcResult::new_error(Error::DIV, cell, "Division by 0".to_string()); } if result.is_nan() { return CalcResult::new_error(Error::NUM, cell, "Invalid data for RRI".to_string()); } CalcResult::Number(result) } // This next three functions deal with Treasure Bills or T-Bills for short // They are zero-coupon that mature in one year or less. // Definitions: // $r$ be the discount rate // $v$ the face value of the Bill // $p$ the price of the Bill // $d_m$ is the number of days from the settlement to maturity // Then: // $$ p = v \times\left(1-\frac{d_m}{r}\right) $$ // If d_m is less than 183 days the he Bond Equivalent Yield (BEY, here $y$) is given by: // $$ y = \frac{F - B}{M}\times \frac{365}{d_m} = \frac{365\times r}{360-r\times d_m} // If d_m>= 183 days things are a bit more complicated. // Let $d_e = d_m - 365/2$ if $d_m <= 365$ or $d_e = 183$ if $d_m = 366$. // $$ v = p\times \left(1+\frac{y}{2}\right)\left(1+d_e\times\frac{y}{365}\right) $$ // Together with the previous relation of $p$ and $v$ gives us a quadratic equation for $y$. // TBILLEQ(settlement, maturity, discount) pub(crate) fn fn_tbilleq(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 3 { return CalcResult::new_args_number_error(cell); } let settlement = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let maturity = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let discount = match self.get_number_no_bools(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let less_than_one_year = match is_less_than_one_year(settlement as i64, maturity as i64) { Ok(f) => f, Err(_) => return CalcResult::new_error(Error::NUM, cell, "Invalid date".to_string()), }; if settlement > maturity { return CalcResult::new_error( Error::NUM, cell, "settlement should be <= maturity".to_string(), ); } if !less_than_one_year { return CalcResult::new_error( Error::NUM, cell, "maturity <= settlement + year".to_string(), ); } if discount <= 0.0 { return CalcResult::new_error(Error::NUM, cell, "discount should be >0".to_string()); } // days to maturity let d_m = maturity - settlement; let result = if d_m < 183.0 { 365.0 * discount / (360.0 - discount * d_m) } else { // Equation here is: // (1-days*rate/360)*(1+y/2)*(1+d_extra*y/year)=1 let year = if d_m == 366.0 { 366.0 } else { 365.0 }; let d_extra = d_m - year / 2.0; let alpha = 1.0 - d_m * discount / 360.0; let beta = 0.5 + d_extra / year; // ay^2+by+c=0 let a = d_extra * alpha / (year * 2.0); let b = alpha * beta; let c = alpha - 1.0; (-b + (b * b - 4.0 * a * c).sqrt()) / (2.0 * a) }; if result.is_infinite() { return CalcResult::new_error(Error::DIV, cell, "Division by 0".to_string()); } if result.is_nan() { return CalcResult::new_error(Error::NUM, cell, "Invalid data for RRI".to_string()); } CalcResult::Number(result) } // TBILLPRICE(settlement, maturity, discount) pub(crate) fn fn_tbillprice(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 3 { return CalcResult::new_args_number_error(cell); } let settlement = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let maturity = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let discount = match self.get_number_no_bools(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let less_than_one_year = match is_less_than_one_year(settlement as i64, maturity as i64) { Ok(f) => f, Err(_) => return CalcResult::new_error(Error::NUM, cell, "Invalid date".to_string()), }; if settlement > maturity { return CalcResult::new_error( Error::NUM, cell, "settlement should be <= maturity".to_string(), ); } if !less_than_one_year { return CalcResult::new_error( Error::NUM, cell, "maturity <= settlement + year".to_string(), ); } if discount <= 0.0 { return CalcResult::new_error(Error::NUM, cell, "discount should be >0".to_string()); } // days to maturity let d_m = maturity - settlement; let result = 100.0 * (1.0 - discount * d_m / 360.0); if result.is_infinite() { return CalcResult::new_error(Error::DIV, cell, "Division by 0".to_string()); } if result.is_nan() || result < 0.0 { return CalcResult::new_error(Error::NUM, cell, "Invalid data for RRI".to_string()); } CalcResult::Number(result) } // TBILLYIELD(settlement, maturity, pr) pub(crate) fn fn_tbillyield(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 3 { return CalcResult::new_args_number_error(cell); } let settlement = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let maturity = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let pr = match self.get_number_no_bools(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let less_than_one_year = match is_less_than_one_year(settlement as i64, maturity as i64) { Ok(f) => f, Err(_) => return CalcResult::new_error(Error::NUM, cell, "Invalid date".to_string()), }; if settlement > maturity { return CalcResult::new_error( Error::NUM, cell, "settlement should be <= maturity".to_string(), ); } if !less_than_one_year { return CalcResult::new_error( Error::NUM, cell, "maturity <= settlement + year".to_string(), ); } if pr <= 0.0 { return CalcResult::new_error(Error::NUM, cell, "discount should be >0".to_string()); } let days = maturity - settlement; let result = (100.0 - pr) * 360.0 / (pr * days); CalcResult::Number(result) } // DOLLARDE(fractional_dollar, fraction) pub(crate) fn fn_dollarde(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 2 { return CalcResult::new_args_number_error(cell); } let fractional_dollar = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let mut fraction = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; if fraction < 0.0 { return CalcResult::new_error(Error::NUM, cell, "fraction should be >= 1".to_string()); } if fraction < 1.0 { // this is not necessarily DIV/0 return CalcResult::new_error(Error::DIV, cell, "fraction should be >= 1".to_string()); } fraction = fraction.trunc(); while fraction > 10.0 { fraction /= 10.0; } let t = fractional_dollar.trunc(); let result = t + (fractional_dollar - t) * 10.0 / fraction; CalcResult::Number(result) } // DOLLARFR(decimal_dollar, fraction) pub(crate) fn fn_dollarfr(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 2 { return CalcResult::new_args_number_error(cell); } let decimal_dollar = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let mut fraction = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; if fraction < 0.0 { return CalcResult::new_error(Error::NUM, cell, "fraction should be >= 1".to_string()); } if fraction < 1.0 { // this is not necessarily DIV/0 return CalcResult::new_error(Error::DIV, cell, "fraction should be >= 1".to_string()); } fraction = fraction.trunc(); while fraction > 10.0 { fraction /= 10.0; } let t = decimal_dollar.trunc(); let result = t + (decimal_dollar - t) * fraction / 10.0; CalcResult::Number(result) } // CUMIPMT(rate, nper, pv, start_period, end_period, type) pub(crate) fn fn_cumipmt(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 6 { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let nper = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let pv = match self.get_number_no_bools(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let start_period = match self.get_number_no_bools(&args[3], cell) { Ok(f) => f.ceil() as i32, Err(s) => return s, }; let end_period = match self.get_number_no_bools(&args[4], cell) { Ok(f) => f.trunc() as i32, Err(s) => return s, }; // 0 at the end of the period, 1 at the beginning of the period let period_type = match self.get_number_no_bools(&args[5], cell) { Ok(f) => { if f == 0.0 { false } else if f == 1.0 { true } else { return CalcResult::new_error( Error::NUM, cell, "invalid period type".to_string(), ); } } Err(s) => return s, }; if start_period > end_period { return CalcResult::new_error( Error::NUM, cell, "start period should come before end period".to_string(), ); } if rate <= 0.0 || nper <= 0.0 || pv <= 0.0 || start_period < 1 { return CalcResult::new_error(Error::NUM, cell, "invalid parameters".to_string()); } let mut result = 0.0; for period in start_period..=end_period { result += match compute_ipmt(rate, period as f64, nper, pv, 0.0, period_type) { Ok(f) => f, Err(error) => { return CalcResult::Error { error: error.0, origin: cell, message: error.1, } } } } CalcResult::Number(result) } // CUMPRINC(rate, nper, pv, start_period, end_period, type) pub(crate) fn fn_cumprinc(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { if args.len() != 6 { return CalcResult::new_args_number_error(cell); } let rate = match self.get_number_no_bools(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let nper = match self.get_number_no_bools(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let pv = match self.get_number_no_bools(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let start_period = match self.get_number_no_bools(&args[3], cell) { Ok(f) => f.ceil() as i32, Err(s) => return s, }; let end_period = match self.get_number_no_bools(&args[4], cell) { Ok(f) => f.trunc() as i32, Err(s) => return s, }; // 0 at the end of the period, 1 at the beginning of the period let period_type = match self.get_number_no_bools(&args[5], cell) { Ok(f) => { if f == 0.0 { false } else if f == 1.0 { true } else { return CalcResult::new_error( Error::NUM, cell, "invalid period type".to_string(), ); } } Err(s) => return s, }; if start_period > end_period { return CalcResult::new_error( Error::NUM, cell, "start period should come before end period".to_string(), ); } if rate <= 0.0 || nper <= 0.0 || pv <= 0.0 || start_period < 1 { return CalcResult::new_error(Error::NUM, cell, "invalid parameters".to_string()); } let mut result = 0.0; for period in start_period..=end_period { result += match compute_ppmt(rate, period as f64, nper, pv, 0.0, period_type) { Ok(f) => f, Err(error) => { return CalcResult::Error { error: error.0, origin: cell, message: error.1, } } } } CalcResult::Number(result) } // DDB(cost, salvage, life, period, [factor]) pub(crate) fn fn_ddb(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(4..=5).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let cost = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let salvage = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let life = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let period = match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, }; // The rate at which the balance declines. let factor = if arg_count > 4 { match self.get_number_no_bools(&args[4], cell) { Ok(f) => f, Err(s) => return s, } } else { // If factor is omitted, it is assumed to be 2 (the double-declining balance method). 2.0 }; if period > life || cost < 0.0 || salvage < 0.0 || period <= 0.0 || factor <= 0.0 { return CalcResult::new_error(Error::NUM, cell, "invalid parameters".to_string()); }; // let period_trunc = period.floor() as i32; let mut rate = factor / life; if rate > 1.0 { rate = 1.0 }; let value = if rate == 1.0 { if period == 1.0 { cost } else { 0.0 } } else { cost * (1.0 - rate).powf(period - 1.0) }; let new_value = cost * (1.0 - rate).powf(period); let result = f64::max(value - f64::max(salvage, new_value), 0.0); CalcResult::Number(result) } // DB(cost, salvage, life, period, [month]) pub(crate) fn fn_db(&mut self, args: &[Node], cell: CellReferenceIndex) -> CalcResult { let arg_count = args.len(); if !(4..=5).contains(&arg_count) { return CalcResult::new_args_number_error(cell); } let cost = match self.get_number(&args[0], cell) { Ok(f) => f, Err(s) => return s, }; let salvage = match self.get_number(&args[1], cell) { Ok(f) => f, Err(s) => return s, }; let life = match self.get_number(&args[2], cell) { Ok(f) => f, Err(s) => return s, }; let period = match self.get_number(&args[3], cell) { Ok(f) => f, Err(s) => return s, }; let month = if arg_count > 4 { match self.get_number_no_bools(&args[4], cell) { Ok(f) => f.trunc(), Err(s) => return s, } } else { 12.0 }; if month == 12.0 && period > life || (period > life + 1.0) || month <= 0.0 || month > 12.0 || period <= 0.0 || cost < 0.0 { return CalcResult::new_error(Error::NUM, cell, "invalid parameters".to_string()); }; if cost == 0.0 { return CalcResult::Number(0.0); } // rounded to three decimal places // FIXME: We should have utilities for this (see to_precision) let rate = f64::round((1.0 - f64::powf(salvage / cost, 1.0 / life)) * 1000.0) / 1000.0; let mut result = cost * rate * month / 12.0; let period = period.floor() as i32; let life = life.floor() as i32; // Depreciation for the first and last periods is a special case. if period == 1 { return CalcResult::Number(result); }; for _ in 0..period - 2 { result += (cost - result) * rate; } if period == life + 1 { // last period return CalcResult::Number((cost - result) * rate * (12.0 - month) / 12.0); } CalcResult::Number(rate * (cost - result)) } }