function BVHelp(form) {
alert("This feature is not yet implemented.");
}
function randomBVProblem(form) {
theF = 1000;
theCR = Math.round((Math.random()*16+4)*10)/10;
theB = Math.round((Math.random()*400+800)*100)/100;
theM = Math.round(Math.random()*29+1);
form.BInput.value="" + theB;
form.FInput.value="" + theF;
form.CRInput.value="" + theCR;
form.MInput.value="" + theM;
form.ROutput.value="";
}
function findBV(form) {
theFStr = form.FInput.value;
if (!isPositiveNumber(theFStr)) {
return false;
}
theCRStr = form.CRInput.value;
if (!isPositiveNumber(theCRStr)) {
return false;
}
theBStr = form.BInput.value;
if (!isPositiveNumber(theBStr)) {
return false;
}
theMStr = form.MInput.value;
if (!isPositiveNumber(theMStr)) {
return false;
}
theF = parseFloat(theFStr);
theCR = parseFloat(theCRStr);
theB = parseFloat(theBStr);
theM = parseInt(theMStr);
var theR = calcNR((theCR*theF/200),-theB,theF,theM*2,2);
form.MInput.value = "" + Math.round(theM);
form.ROutput.value = "" + Math.round(theR*100)/100;
return true;
}
function calcPV(inPMT, inFV, inNR, inNP, inC) {
var outPV = inFV*Math.pow((1 + inNR/(100*inC)),(-inNP));
if (inNR == 0) {
outPV = outPV + inPMT*inNP;
} else {
outPV = outPV + inPMT*((1-(Math.pow((1 + inNR/(100*inC)),(-inNP))))/(inNR/(100*inC)));
}
return outPV;
}
function calcNR(inPMT, inPV, inFV, inNP, inC) {
var outNR = 0.1; // initial guess
var thePV1, thePV2, theDeriv;
var theH = 0.00001;
var i = 1;
var theZeros = 0;
var lastNR = outNR;
//alert("PV " + inPV + " PMT " + inPMT + " FV " + inFV + " NP " + inNP);
if (inNP <= 0) { // should throw an exception
alert("The Nominal Rate cannot be computed.");
return outNR = "";
}
if (inFV == 0) {
theZeros++;
}
if (inPMT == 0) {
theZeros++;
}
if (inPV == 0) {
theZeros++;
// inFV *= -1;
}
if (theZeros >= 2) { // should throw an exception
alert("The Nominal Rate cannot be computed.");
return outNR = "";
}
if ((inPV > 0) && (inPMT >= 0) && (inFV >= 0)) {
alert("The Nominal Rate cannot be computed.");
return outNR = "";
}
if ((inPV == 0) && (inPMT >= 0) && (inFV >= 0)) {
alert("The Nominal Rate cannot be computed.");
return outNR = "";
}
inPV *= -1;
//thePV1 = calcPV(inPMT,inFV,outNR*100,inNP,inC);
//alert("thePV1 " + thePV1 + " " + inPV);
do {
thePV1 = calcPV(inPMT,inFV,(outNR*100),inNP,inC) - inPV;
theDeriv = ((calcPV(inPMT,inFV,((outNR+theH)*100),inNP,inC) - inPV) - thePV1)/theH;
thePV2 = thePV1;
//if ((theDeriv == 0) && (Math.abs(thePV2) > 0)) { // should throw an exception
// alert("The Nominal Rate cannot be computed. 5");
// return outNR = "";
//}
lastNR = outNR;
outNR = outNR - thePV1/theDeriv;
if (i > 200) { // should throw an exception
alert("The Nominal Rate cannot be computed.");
return outNR = "";
}
i++;
if (thePV2 < 0) thePV2 *= -1;
} while (thePV2 > 0.0001);
return (lastNR*100); // maybe should change to give the previous rate
}
function calcBVHelp(form) {
theFStr = form.FInput.value;
if (!isPositiveNumber(theFStr)) {
return false;
}
theCRStr = form.CRInput.value;
if (!isPositiveNumber(theCRStr)) {
return false;
}
theBStr = form.BInput.value;
if (!isPositiveNumber(theBStr)) {
return false;
}
theMStr = form.MInput.value;
if (!isPositiveNumber(theMStr)) {
return false;
}
theF = parseFloat(theFStr);
theCR = parseFloat(theCRStr);
theB = parseFloat(theBStr);
theM = parseInt(theMStr);
var theR = calcNR((theCR*theF/200),-theB,theF,theM*2,2);
form.ROutput.value = "" + Math.round(theR*100)/100;
var theOut = "Yield to Maturity Help";
theOut += "Yield to Maturity Help
";
theOut += "To solve using the Texas Instruments BA II Plus Calculator:
";
theOut += "Make sure that the calculator is set up for semiannual compounding before beginning.
";
theOut += "| -" + Math.round(theB*100)/100 + " | [PV] |
";
theOut += "| " + Math.round(theF*100)/100 + " | [FV] |
";
theOut += "| " + Math.round((theCR*theF/200)*100)/100 + " | [PMT] |
";
theOut += "| " + Math.round(theM*2) + " | [N] |
";
theOut += "| | [CPT][I/Y] |
";
theOut += "The Yield to Maturity is " + Math.round(theR*100)/100 + "\%
";
theOut += "";
theOut += "";
theOut += "";
var newWin = window.open("","","scrollbars,resizable,width=400,height=420");
if (newWin != null) {
newWin.document.write(theOut);
newWin.document.close();
newWin.focus();
}
return true;
}
function isPositiveNumber(inputStr) {
for (var i = 0; i < inputStr.length; i++) {
var oneChar = inputStr.substring(i,i+1);
if (((oneChar >= "0") && (oneChar <= "9")) || (oneChar == ".")) {
} else {
alert("Please make sure that only numbers are input.");
return false;
}
}
return true;
}
function isNegativeNumber(inputStr) {
if (inputStr.length < 2) {
alert("Please input a negative number.");
return false;
}
var oneChar = inputStr.substring(0,1);
if (oneChar != '-') {
alert("Please make sure that only negative numbers are input.");
return false;
}
for (var i = 1; i < inputStr.length; i++) {
oneChar = inputStr.substring(i,i+1);
if (((oneChar >= "0") && (oneChar <= "9")) || (oneChar == ".")) {
} else {
alert("Please make sure that only numbers are input.");
return false;
}
}
return true;
}