financial - npm Package Compare versions

Comparing version 0.0.16 to 0.0.17

dist/financial.cjs.development.js

@@ -461,2 +461,123 @@ 'use strict';
 /**
+ * Return the Internal Rate of Return (IRR).
+ *
+ * This is the "average" periodically compounded rate of return
+ * that gives a net present value of 0.0; for a more complete
+ * explanation, see Notes below.
+ *
+ * @param values - Input cash flows per time period.
+ *   By convention, net "deposits"
+ *   are negative and net "withdrawals" are positive.  Thus, for
+ *   example, at least the first element of `values`, which represents
+ *   the initial investment, will typically be negative.
+ * @param guess - Starting guess for solving the Internal Rate of Return
+ * @param tol - Required tolerance for the solution
+ * @param maxIter - Maximum iterations in finding the solution
+ *
+ * @returns Internal Rate of Return for periodic input values
+ *
+ * ## Notes
+ *
+ * The IRR is perhaps best understood through an example (illustrated
+ * using `irr` in the Examples section below).
+ *
+ * Suppose one invests 100
+ * units and then makes the following withdrawals at regular (fixed)
+ * intervals: 39, 59, 55, 20.  Assuming the ending value is 0, one's 100
+ * unit investment yields 173 units; however, due to the combination of
+ * compounding and the periodic withdrawals, the "average" rate of return
+ * is neither simply 0.73/4 nor (1.73)^0.25-1.
+ * Rather, it is the solution (for `r`) of the equation:
+ *
+ * ```
+ * -100 + 39/(1+r) + 59/((1+r)^2) + 55/((1+r)^3) + 20/((1+r)^4) = 0
+ * ```
+ *
+ * In general, for `values` = `[0, 1, ... M]`,
+ * `irr` is the solution of the equation:
+ *
+ * ```
+ * \\sum_{t=0}^M{\\frac{v_t}{(1+irr)^{t}}} = 0
+ * ```
+ *
+ * ## Example
+ *
+ * ```javascript
+ * import { irr } from 'financial'
+ *
+ * irr([-100, 39, 59, 55, 20]) // 0.28095
+ * irr([-100, 0, 0, 74]) // -0.0955
+ * irr([-100, 100, 0, -7]) // -0.0833
+ * irr([-100, 100, 0, 7]) // 0.06206
+ * irr([-5, 10.5, 1, -8, 1]) // 0.0886
+ * ```
+ *
+ * ## References
+ *
+ * - L. J. Gitman, "Principles of Managerial Finance, Brief," 3rd ed.,
+ *  Addison-Wesley, 2003, pg. 348.
+ */
+
+function irr(values, guess, tol, maxIter) {
+  if (guess === void 0) {
+    guess = 0.1;
+  }
+
+  if (tol === void 0) {
+    tol = 1e-6;
+  }
+
+  if (maxIter === void 0) {
+    maxIter = 100;
+  }
+
+  // Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+  // ASF licensed (check the link for the full license)
+  // Credits: algorithm inspired by Apache OpenOffice
+  // Initialize dates and check that values contains at
+  // least one positive value and one negative value
+  var dates = [];
+  var positive = false;
+  var negative = false;
+
+  for (var i = 0; i < values.length; i++) {
+    dates[i] = i === 0 ? 0 : dates[i - 1] + 365;
+
+    if (values[i] > 0) {
+      positive = true;
+    }
+
+    if (values[i] < 0) {
+      negative = true;
+    }
+  } // Return error if values does not contain at least one positive value and one negative value
+
+
+  if (!positive || !negative) {
+    return Number.NaN;
+  } // Initialize guess and resultRate
+
+
+  var resultRate = guess; // Implement Newton's method
+
+  var newRate, epsRate, resultValue;
+  var iteration = 0;
+  var contLoop = true;
+
+  do {
+    resultValue = _irrResult(values, dates, resultRate);
+    newRate = resultRate - resultValue / _irrResultDeriv(values, dates, resultRate);
+    epsRate = Math.abs(newRate - resultRate);
+    resultRate = newRate;
+    contLoop = epsRate > tol && Math.abs(resultValue) > tol;
+  } while (contLoop && ++iteration < maxIter);
+
+  if (contLoop) {
+    return Number.NaN;
+  } // Return internal rate of return
+
+
+  return resultRate;
+}
+/**
  * This function is here to simply have a different name for the 'fv'
@@ -492,5 +613,47 @@ * function to not interfere with the 'fv' keyword argument within the 'ipmt'
 }
+/**
+ * Calculates the resulting amount.
+ *
+ * Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+ * ASF licensed (check the link for the full license)
+ *
+ * @private
+ */
 
+
+function _irrResult(values, dates, rate) {
+  var r = rate + 1;
+  var result = values[0];
+
+  for (var i = 1; i < values.length; i++) {
+    result += values[i] / Math.pow(r, (dates[i] - dates[0]) / 365);
+  }
+
+  return result;
+}
+/**
+ * Calculates the first derivation
+ *
+ * Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+ * ASF licensed (check the link for the full license)
+ *
+ * @private
+ */
+
+
+function _irrResultDeriv(values, dates, rate) {
+  var r = rate + 1;
+  var result = 0;
+
+  for (var i = 1; i < values.length; i++) {
+    var frac = (dates[i] - dates[0]) / 365;
+    result -= frac * values[i] / Math.pow(r, frac + 1);
+  }
+
+  return result;
+}
+
 exports.fv = fv;
 exports.ipmt = ipmt;
+exports.irr = irr;
 exports.nper = nper;
@@ -497,0 +660,0 @@ exports.pmt = pmt;

dist/financial.cjs.production.min.js

@@ -1,2 +0,2 @@
-"use strict";var e;function t(e,t,n,r,o){if(void 0===o&&(o=exports.PaymentDueTime.End),0===e)return-(r+n*t);var i=Math.pow(1+e,t);return-r*i-n*(1+e*(o===exports.PaymentDueTime.Begin?1:0))/e*(i-1)}function n(e,t,n,r,o){void 0===r&&(r=0),void 0===o&&(o=exports.PaymentDueTime.End);var i=0===e,u=Math.pow(1+e,t),a=o===exports.PaymentDueTime.Begin?1:0,m=i?1:e;return-(r+n*u)/(i?t:(1+m*a)*(u-1)/m)}function r(e,t,r,i,u,a){if(void 0===u&&(u=0),void 0===a&&(a=exports.PaymentDueTime.End),t<1)return Number.NaN;if(a===exports.PaymentDueTime.Begin&&1===t)return 0;var m=o(e,t,n(e,r,i,u,a),i,a)*e;return a===exports.PaymentDueTime.Begin&&t>1&&(m/=1+e),m}function o(e,n,r,o,i){return t(e,n-1,r,o,i)}function i(e,t,n,r,o,i){var u=i===exports.PaymentDueTime.Begin?1:0,a=Math.pow(e+1,t),m=Math.pow(e+1,t-1);return(o+a*r+n*(a-1)*(e*u+1)/e)/(t*m*r-n*(a-1)*(e*u+1)/Math.pow(e,2)+t*n*m*(e*u+1)/e+n*(a-1)*u/e)}Object.defineProperty(exports,"__esModule",{value:!0}),(e=exports.PaymentDueTime||(exports.PaymentDueTime={})).Begin="begin",e.End="end",exports.fv=t,exports.ipmt=r,exports.nper=function(e,t,n,r,o){if(void 0===r&&(r=0),void 0===o&&(o=exports.PaymentDueTime.End),0===e)return-(r+n)/t;var i=t*(1+e*(o===exports.PaymentDueTime.Begin?1:0))/e;return Math.log((-r+i)/(n+i))/Math.log(1+e)},exports.pmt=n,exports.ppmt=function(e,t,o,i,u,a){return void 0===u&&(u=0),void 0===a&&(a=exports.PaymentDueTime.End),n(e,o,i,u,a)-r(e,t,o,i,u,a)},exports.pv=function(e,t,n,r,o){void 0===r&&(r=0),void 0===o&&(o=exports.PaymentDueTime.End);var i=o===exports.PaymentDueTime.Begin?1:0,u=0===e,a=Math.pow(1+e,t);return-(r+n*(u?t:(1+e*i)*(a-1)/e))/a},exports.rate=function(e,t,n,r,o,u,a,m){void 0===o&&(o=exports.PaymentDueTime.End),void 0===u&&(u=.1),void 0===a&&(a=1e-6),void 0===m&&(m=100);for(var p=u,s=0,v=!1;s<m&&!v;){var d=p-i(p,e,t,n,r,o);v=Math.abs(d-p)<a,s++,p=d}return v?p:Number.NaN};
+"use strict";var e;function t(e,t,r,n,o){if(void 0===o&&(o=exports.PaymentDueTime.End),0===e)return-(n+r*t);var i=Math.pow(1+e,t);return-n*i-r*(1+e*(o===exports.PaymentDueTime.Begin?1:0))/e*(i-1)}function r(e,t,r,n,o){void 0===n&&(n=0),void 0===o&&(o=exports.PaymentDueTime.End);var i=0===e,a=Math.pow(1+e,t),u=o===exports.PaymentDueTime.Begin?1:0,p=i?1:e;return-(n+r*a)/(i?t:(1+p*u)*(a-1)/p)}function n(e,t,n,i,a,u){if(void 0===a&&(a=0),void 0===u&&(u=exports.PaymentDueTime.End),t<1)return Number.NaN;if(u===exports.PaymentDueTime.Begin&&1===t)return 0;var p=o(e,t,r(e,n,i,a,u),i,u)*e;return u===exports.PaymentDueTime.Begin&&t>1&&(p/=1+e),p}function o(e,r,n,o,i){return t(e,r-1,n,o,i)}function i(e,t,r,n,o,i){var a=i===exports.PaymentDueTime.Begin?1:0,u=Math.pow(e+1,t),p=Math.pow(e+1,t-1);return(o+u*n+r*(u-1)*(e*a+1)/e)/(t*p*n-r*(u-1)*(e*a+1)/Math.pow(e,2)+t*r*p*(e*a+1)/e+r*(u-1)*a/e)}function a(e,t,r){for(var n=r+1,o=e[0],i=1;i<e.length;i++)o+=e[i]/Math.pow(n,(t[i]-t[0])/365);return o}function u(e,t,r){for(var n=r+1,o=0,i=1;i<e.length;i++){var a=(t[i]-t[0])/365;o-=a*e[i]/Math.pow(n,a+1)}return o}Object.defineProperty(exports,"__esModule",{value:!0}),(e=exports.PaymentDueTime||(exports.PaymentDueTime={})).Begin="begin",e.End="end",exports.fv=t,exports.ipmt=n,exports.irr=function(e,t,r,n){void 0===t&&(t=.1),void 0===r&&(r=1e-6),void 0===n&&(n=100);for(var o=[],i=!1,p=!1,m=0;m<e.length;m++)o[m]=0===m?0:o[m-1]+365,e[m]>0&&(i=!0),e[m]<0&&(p=!0);if(!i||!p)return Number.NaN;var v,s,d,x=t,f=0,h=!0;do{v=x-(d=a(e,o,x))/u(e,o,x),s=Math.abs(v-x),x=v,h=s>r&&Math.abs(d)>r}while(h&&++f<n);return h?Number.NaN:x},exports.nper=function(e,t,r,n,o){if(void 0===n&&(n=0),void 0===o&&(o=exports.PaymentDueTime.End),0===e)return-(n+r)/t;var i=t*(1+e*(o===exports.PaymentDueTime.Begin?1:0))/e;return Math.log((-n+i)/(r+i))/Math.log(1+e)},exports.pmt=r,exports.ppmt=function(e,t,o,i,a,u){return void 0===a&&(a=0),void 0===u&&(u=exports.PaymentDueTime.End),r(e,o,i,a,u)-n(e,t,o,i,a,u)},exports.pv=function(e,t,r,n,o){void 0===n&&(n=0),void 0===o&&(o=exports.PaymentDueTime.End);var i=o===exports.PaymentDueTime.Begin?1:0,a=0===e,u=Math.pow(1+e,t);return-(n+r*(a?t:(1+e*i)*(u-1)/e))/u},exports.rate=function(e,t,r,n,o,a,u,p){void 0===o&&(o=exports.PaymentDueTime.End),void 0===a&&(a=.1),void 0===u&&(u=1e-6),void 0===p&&(p=100);for(var m=a,v=0,s=!1;v<p&&!s;){var d=m-i(m,e,t,r,n,o);s=Math.abs(d-m)<u,v++,m=d}return s?m:Number.NaN};
 //# sourceMappingURL=financial.cjs.production.min.js.map

dist/financial.d.ts

@@ -308,1 +308,61 @@ /**
 export declare function rate(nper: number, pmt: number, pv: number, fv: number, when?: PaymentDueTime, guess?: number, tol?: number, maxIter?: number): number;
+/**
+ * Return the Internal Rate of Return (IRR).
+ *
+ * This is the "average" periodically compounded rate of return
+ * that gives a net present value of 0.0; for a more complete
+ * explanation, see Notes below.
+ *
+ * @param values - Input cash flows per time period.
+ *   By convention, net "deposits"
+ *   are negative and net "withdrawals" are positive.  Thus, for
+ *   example, at least the first element of `values`, which represents
+ *   the initial investment, will typically be negative.
+ * @param guess - Starting guess for solving the Internal Rate of Return
+ * @param tol - Required tolerance for the solution
+ * @param maxIter - Maximum iterations in finding the solution
+ *
+ * @returns Internal Rate of Return for periodic input values
+ *
+ * ## Notes
+ *
+ * The IRR is perhaps best understood through an example (illustrated
+ * using `irr` in the Examples section below).
+ *
+ * Suppose one invests 100
+ * units and then makes the following withdrawals at regular (fixed)
+ * intervals: 39, 59, 55, 20.  Assuming the ending value is 0, one's 100
+ * unit investment yields 173 units; however, due to the combination of
+ * compounding and the periodic withdrawals, the "average" rate of return
+ * is neither simply 0.73/4 nor (1.73)^0.25-1.
+ * Rather, it is the solution (for `r`) of the equation:
+ *
+ * ```
+ * -100 + 39/(1+r) + 59/((1+r)^2) + 55/((1+r)^3) + 20/((1+r)^4) = 0
+ * ```
+ *
+ * In general, for `values` = `[0, 1, ... M]`,
+ * `irr` is the solution of the equation:
+ *
+ * ```
+ * \\sum_{t=0}^M{\\frac{v_t}{(1+irr)^{t}}} = 0
+ * ```
+ *
+ * ## Example
+ *
+ * ```javascript
+ * import { irr } from 'financial'
+ *
+ * irr([-100, 39, 59, 55, 20]) // 0.28095
+ * irr([-100, 0, 0, 74]) // -0.0955
+ * irr([-100, 100, 0, -7]) // -0.0833
+ * irr([-100, 100, 0, 7]) // 0.06206
+ * irr([-5, 10.5, 1, -8, 1]) // 0.0886
+ * ```
+ *
+ * ## References
+ *
+ * - L. J. Gitman, "Principles of Managerial Finance, Brief," 3rd ed.,
+ *  Addison-Wesley, 2003, pg. 348.
+ */
+export declare function irr(values: number[], guess?: number, tol?: number, maxIter?: number): number;

dist/financial.esm.js

@@ -458,2 +458,123 @@ /**
 /**
+ * Return the Internal Rate of Return (IRR).
+ *
+ * This is the "average" periodically compounded rate of return
+ * that gives a net present value of 0.0; for a more complete
+ * explanation, see Notes below.
+ *
+ * @param values - Input cash flows per time period.
+ *   By convention, net "deposits"
+ *   are negative and net "withdrawals" are positive.  Thus, for
+ *   example, at least the first element of `values`, which represents
+ *   the initial investment, will typically be negative.
+ * @param guess - Starting guess for solving the Internal Rate of Return
+ * @param tol - Required tolerance for the solution
+ * @param maxIter - Maximum iterations in finding the solution
+ *
+ * @returns Internal Rate of Return for periodic input values
+ *
+ * ## Notes
+ *
+ * The IRR is perhaps best understood through an example (illustrated
+ * using `irr` in the Examples section below).
+ *
+ * Suppose one invests 100
+ * units and then makes the following withdrawals at regular (fixed)
+ * intervals: 39, 59, 55, 20.  Assuming the ending value is 0, one's 100
+ * unit investment yields 173 units; however, due to the combination of
+ * compounding and the periodic withdrawals, the "average" rate of return
+ * is neither simply 0.73/4 nor (1.73)^0.25-1.
+ * Rather, it is the solution (for `r`) of the equation:
+ *
+ * ```
+ * -100 + 39/(1+r) + 59/((1+r)^2) + 55/((1+r)^3) + 20/((1+r)^4) = 0
+ * ```
+ *
+ * In general, for `values` = `[0, 1, ... M]`,
+ * `irr` is the solution of the equation:
+ *
+ * ```
+ * \\sum_{t=0}^M{\\frac{v_t}{(1+irr)^{t}}} = 0
+ * ```
+ *
+ * ## Example
+ *
+ * ```javascript
+ * import { irr } from 'financial'
+ *
+ * irr([-100, 39, 59, 55, 20]) // 0.28095
+ * irr([-100, 0, 0, 74]) // -0.0955
+ * irr([-100, 100, 0, -7]) // -0.0833
+ * irr([-100, 100, 0, 7]) // 0.06206
+ * irr([-5, 10.5, 1, -8, 1]) // 0.0886
+ * ```
+ *
+ * ## References
+ *
+ * - L. J. Gitman, "Principles of Managerial Finance, Brief," 3rd ed.,
+ *  Addison-Wesley, 2003, pg. 348.
+ */
+
+function irr(values, guess, tol, maxIter) {
+  if (guess === void 0) {
+    guess = 0.1;
+  }
+
+  if (tol === void 0) {
+    tol = 1e-6;
+  }
+
+  if (maxIter === void 0) {
+    maxIter = 100;
+  }
+
+  // Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+  // ASF licensed (check the link for the full license)
+  // Credits: algorithm inspired by Apache OpenOffice
+  // Initialize dates and check that values contains at
+  // least one positive value and one negative value
+  var dates = [];
+  var positive = false;
+  var negative = false;
+
+  for (var i = 0; i < values.length; i++) {
+    dates[i] = i === 0 ? 0 : dates[i - 1] + 365;
+
+    if (values[i] > 0) {
+      positive = true;
+    }
+
+    if (values[i] < 0) {
+      negative = true;
+    }
+  } // Return error if values does not contain at least one positive value and one negative value
+
+
+  if (!positive || !negative) {
+    return Number.NaN;
+  } // Initialize guess and resultRate
+
+
+  var resultRate = guess; // Implement Newton's method
+
+  var newRate, epsRate, resultValue;
+  var iteration = 0;
+  var contLoop = true;
+
+  do {
+    resultValue = _irrResult(values, dates, resultRate);
+    newRate = resultRate - resultValue / _irrResultDeriv(values, dates, resultRate);
+    epsRate = Math.abs(newRate - resultRate);
+    resultRate = newRate;
+    contLoop = epsRate > tol && Math.abs(resultValue) > tol;
+  } while (contLoop && ++iteration < maxIter);
+
+  if (contLoop) {
+    return Number.NaN;
+  } // Return internal rate of return
+
+
+  return resultRate;
+}
+/**
  * This function is here to simply have a different name for the 'fv'
@@ -489,4 +610,45 @@ * function to not interfere with the 'fv' keyword argument within the 'ipmt'
 }
+/**
+ * Calculates the resulting amount.
+ *
+ * Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+ * ASF licensed (check the link for the full license)
+ *
+ * @private
+ */
 
-export { PaymentDueTime, fv, ipmt, nper, pmt, ppmt, pv, rate };
+
+function _irrResult(values, dates, rate) {
+  var r = rate + 1;
+  var result = values[0];
+
+  for (var i = 1; i < values.length; i++) {
+    result += values[i] / Math.pow(r, (dates[i] - dates[0]) / 365);
+  }
+
+  return result;
+}
+/**
+ * Calculates the first derivation
+ *
+ * Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+ * ASF licensed (check the link for the full license)
+ *
+ * @private
+ */
+
+
+function _irrResultDeriv(values, dates, rate) {
+  var r = rate + 1;
+  var result = 0;
+
+  for (var i = 1; i < values.length; i++) {
+    var frac = (dates[i] - dates[0]) / 365;
+    result -= frac * values[i] / Math.pow(r, frac + 1);
+  }
+
+  return result;
+}
+
+export { PaymentDueTime, fv, ipmt, irr, nper, pmt, ppmt, pv, rate };
 //# sourceMappingURL=financial.esm.js.map

package.json

@@ -5,3 +5,3 @@ {
   "author": "Luciano Mammino <[e-mail]> (https://loige.co)",
-  "version": "0.0.16",
+  "version": "0.0.17",
   "repository": {
@@ -8,0 +8,0 @@ "type": "git",

README.md

@@ -91,3 +91,3 @@ # Financial
  - [X] `rate`
- - [ ] `irr`
+ - [X] `irr`
  - [ ] `npv`
@@ -94,0 +94,0 @@ - [ ] `mirr`

src/financial.ts

@@ -399,2 +399,109 @@ /**
 /**
+ * Return the Internal Rate of Return (IRR).
+ *
+ * This is the "average" periodically compounded rate of return
+ * that gives a net present value of 0.0; for a more complete
+ * explanation, see Notes below.
+ *
+ * @param values - Input cash flows per time period.
+ *   By convention, net "deposits"
+ *   are negative and net "withdrawals" are positive.  Thus, for
+ *   example, at least the first element of `values`, which represents
+ *   the initial investment, will typically be negative.
+ * @param guess - Starting guess for solving the Internal Rate of Return
+ * @param tol - Required tolerance for the solution
+ * @param maxIter - Maximum iterations in finding the solution
+ *
+ * @returns Internal Rate of Return for periodic input values
+ *
+ * ## Notes
+ *
+ * The IRR is perhaps best understood through an example (illustrated
+ * using `irr` in the Examples section below).
+ *
+ * Suppose one invests 100
+ * units and then makes the following withdrawals at regular (fixed)
+ * intervals: 39, 59, 55, 20.  Assuming the ending value is 0, one's 100
+ * unit investment yields 173 units; however, due to the combination of
+ * compounding and the periodic withdrawals, the "average" rate of return
+ * is neither simply 0.73/4 nor (1.73)^0.25-1.
+ * Rather, it is the solution (for `r`) of the equation:
+ *
+ * ```
+ * -100 + 39/(1+r) + 59/((1+r)^2) + 55/((1+r)^3) + 20/((1+r)^4) = 0
+ * ```
+ *
+ * In general, for `values` = `[0, 1, ... M]`,
+ * `irr` is the solution of the equation:
+ *
+ * ```
+ * \\sum_{t=0}^M{\\frac{v_t}{(1+irr)^{t}}} = 0
+ * ```
+ *
+ * ## Example
+ *
+ * ```javascript
+ * import { irr } from 'financial'
+ *
+ * irr([-100, 39, 59, 55, 20]) // 0.28095
+ * irr([-100, 0, 0, 74]) // -0.0955
+ * irr([-100, 100, 0, -7]) // -0.0833
+ * irr([-100, 100, 0, 7]) // 0.06206
+ * irr([-5, 10.5, 1, -8, 1]) // 0.0886
+ * ```
+ *
+ * ## References
+ *
+ * - L. J. Gitman, "Principles of Managerial Finance, Brief," 3rd ed.,
+ *  Addison-Wesley, 2003, pg. 348.
+ */
+export function irr (values: number[], guess = 0.1, tol = 1e-6, maxIter = 100): number {
+  // Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+  // ASF licensed (check the link for the full license)
+  // Credits: algorithm inspired by Apache OpenOffice
+
+  // Initialize dates and check that values contains at
+  // least one positive value and one negative value
+  const dates : number[] = []
+  let positive = false
+  let negative = false
+  for (var i = 0; i < values.length; i++) {
+    dates[i] = (i === 0) ? 0 : dates[i - 1] + 365
+    if (values[i] > 0) {
+      positive = true
+    }
+    if (values[i] < 0) {
+      negative = true
+    }
+  }
+
+  // Return error if values does not contain at least one positive value and one negative value
+  if (!positive || !negative) {
+    return Number.NaN
+  }
+
+  // Initialize guess and resultRate
+  let resultRate = guess
+
+  // Implement Newton's method
+  let newRate, epsRate, resultValue
+  let iteration = 0
+  let contLoop = true
+  do {
+    resultValue = _irrResult(values, dates, resultRate)
+    newRate = resultRate - resultValue / _irrResultDeriv(values, dates, resultRate)
+    epsRate = Math.abs(newRate - resultRate)
+    resultRate = newRate
+    contLoop = (epsRate > tol) && (Math.abs(resultValue) > tol)
+  } while (contLoop && (++iteration < maxIter))
+
+  if (contLoop) {
+    return Number.NaN
+  }
+
+  // Return internal rate of return
+  return resultRate
+}
+
+/**
  * This function is here to simply have a different name for the 'fv'
@@ -432,1 +539,36 @@ * function to not interfere with the 'fv' keyword argument within the 'ipmt'
 }
+
+/**
+ * Calculates the resulting amount.
+ *
+ * Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+ * ASF licensed (check the link for the full license)
+ *
+ * @private
+ */
+function _irrResult (values: number[], dates: number[], rate: number): number {
+  const r = rate + 1
+  let result = values[0]
+  for (let i = 1; i < values.length; i++) {
+    result += values[i] / Math.pow(r, (dates[i] - dates[0]) / 365)
+  }
+  return result
+}
+
+/**
+ * Calculates the first derivation
+ *
+ * Based on https://gist.github.com/ghalimi/4591338 by @ghalimi
+ * ASF licensed (check the link for the full license)
+ *
+ * @private
+ */
+function _irrResultDeriv (values: number[], dates: number[], rate: number) : number {
+  const r = rate + 1
+  let result = 0
+  for (let i = 1; i < values.length; i++) {
+    const frac = (dates[i] - dates[0]) / 365
+    result -= frac * values[i] / Math.pow(r, frac + 1)
+  }
+  return result
+}

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2106

increased by28.89%

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