/** knowledge base for the mortgage prequalifier calculation Canadian mortgages are compounded semi-annually instead of monthly like US mortgages. Monthly Pmt = (P*(((1+i/200)^(1/6)-1))/(1-(((1+i/200)^(1/6)))^-(n*12))) Where: P = principal outstanding ( here we call it as Best-case Mortgage Amount) i = annual interest rate percentage n = number of years Here is a easier to read representation: i 1/6 ( 1 + --- ) - 1 200 Pmt = Principal x ------------------------ i 1/6 -12 x n 1 - [ (1 + --- ) ] 200 Or to convert canadian interest rates to US interest rates: Can. Rate 1/6 US Rate = 1200 x [ ( 1 + --------- ) - 1 ] 200 or as a formula, US Rate = 1200 * ((1 + Can.Rate/200)^(1/6) - 1) You'll note if you plug this into the US formula you get the above formula for payment. Home type from listing type 1 house 2 con/townhouse 3 mobile 4 acreage 5 land it can't be used directly to the hometype for the mortgage prequalifier */ (function(){ var CANNOT_QUALIFY ="We can't pre-qualify you without more information";//L43 var NA="NA";// no value //constant multiplier value for calcuation var TYPE_OF_WORK_MULTIPLIER= 10; var CREDIT_MULTIPLIER=7; var DOWNPAYMENT_SOURCE_MULTIPLIER=10; var HOME_TYPE_MULTIPLIER=5; //mortgage constants var MONTHLY_DEBT_PAYMENT = 0.03;//average monthly debt payment (all kinds of debt) --- I2 var MINIMUM_DOWN_PAYMENT = 0.05;//Minimum downpayment required by law -- I3 var AVERAGE_MORTGAGE_RATE = 0.06;//average mortgage interest rate -- I4 var AVERAGE_MORTGAGE_AMMORTIZATION = 35;//average mortgage ammortization -- I5 , 35 years mortgage var MINIMUM_REQUIRED_GDS = 0.32;//Minumum required GDS -- I6 var MINIMUM_REQUIRED_TDS = 0.40;//Minumum required TDS -- I7 var HEAT = 85;//$85 -- I8 var TOTAL_WEIGHT_AVERAGE = 320;// L39, TYPE_OF_WORK_MULTIPLIER , CREDIT_MULTIPLIER ,DOWNPAYMENT_SOURCE_MULTIPLIER ,HOME_TYPE_MULTIPLIER; var MINIMUM_REQUIRED_AVERAGE = 0.6;//L40 var MINIMUM_LOAN_AMOUNT =150000;//L41 //CMHC - insurence for the morgage -- array var downpaymentRates = new Array(5,10,15,20); //downpayment percentage var insuranceRates = new Array(2.75,2.00,1.75,0.00);//insurance percentage //varibles var annualIncome; //var monthlyIncome = annualIncome/12; var workType; var currentDebts;//current monthly debts var credit; var bankruptcy; var homeType; var downPayment; var downpaymentSource; var estimatedMonthlyCondoFee; var estimatedAnnualTax; //reprot part --- result var preQualifiedMortgage; var maxHousePrice; var monthlyPayment; /** *option 1: client info varified, 0: not varified, only if client info varified then we will calculate the prequalified morgage */ $.MortgagePreQualifier = function(option){ //addChangeEvent();//only acculate when info varified by the server //alert("mortgagePrequalifer info varified: " + option); if(option == "1"){ mortPreQ_calculate(); } } var addChangeEvent = function(){ $("#annualIncome").change(function(){mortPreQ_calculate();}); $("#currentDebts").change(function(){mortPreQ_calculate();}); $("#downpayment").change(function(){mortPreQ_calculate();}); $("#typeOfWork").change(function(){mortPreQ_calculate();}); $("#homeType").change(function(){mortPreQ_calculate();}); $("#typeOfWork").change(function(){mortPreQ_calculate();}); $("#bankruptcy").change(function(){mortPreQ_calculate();}); $("#downpaymentSource").change(function(){mortPreQ_calculate();}); //add back this after debug finished } /** * get all form input value, and check if input should be number but not number then correct them */ var getFormValue = function(){ //get values from the form interface annualIncome = parseFloat($("#annualIncome").val()); if(isNaN(annualIncome)) $("#annualIncome").attr("value","0"); currentDebts = parseFloat($("#currentDebts").val()); if(isNaN(currentDebts)) $("#currentDebts").attr("value","0"); downPayment = parseFloat($("#downpayment").val()); if(isNaN(downPayment)) $("#downpayment").attr("value","0"); estimatedMonthlyCondoFee = parseFloat($("#condoFees").val()); if(isNaN(estimatedMonthlyCondoFee)) $("#condoFees").attr("value","0"); estimatedAnnualTax = parseFloat($("#annualTax").val()); if(isNaN(estimatedAnnualTax)) $("#annualTax").attr("value","0"); // Each of these has a weight attached to it. We need to map the selected option to the weight, before the value of the // option was the weight but this confused the framework as there were duplicates. workType = parseInt($("#typeOfWork").val());//opiton drop down if(isNaN(workType)) workType = 0; switch (workType) { case 0: workType = 0; break; case 1: workType = 10; break; case 2: workType = 9; break; case 3: workType = 8; break; case 4: workType = 7; break; case 5: workType = 6; break; case 6: workType = 6; break; case 7: workType = 6; break; case 8: workType = 5; break; case 9: workType = 0; break; default: workType = 0; } credit = parseInt($("#credit").val()); if(isNaN(credit)) credit = 0; switch (credit) { case 0: credit = 0; break; case 1: credit = 0; break; case 2: credit = 0; break; case 3: credit = 5; break; case 4: credit = 8; break; case 5: credit = 10; break; default: credit = 0; } homeType = parseInt($("#homeType").val()); if(isNaN(homeType)) homeType = 0; switch (homeType) { case 0: homeType = 0; break; case 1: homeType = 10; break; case 2: homeType = 9; break; case 3: homeType = 0; break; case 4: homeType = 7; break; case 5: homeType = 6; break; default: homeType = 0; } downpaymentSource = parseInt($("#downpaymentSource").val()); if(isNaN(downpaymentSource)) downpaymentSource = 0; switch (downpaymentSource) { case 0: downpaymentSource = 0; break; case 1: downpaymentSource = 10; break; case 2: downpaymentSource = 10; break; case 3: downpaymentSource = 10; break; case 4: downpaymentSource = 10; break; case 5: downpaymentSource = 5; break; case 6: downpaymentSource = 5; break; default: downpaymentSource = 0; } bankruptcy = ($("#bankruptcy").attr("checked") == true)?1:0; } /** * */ var mortPreQ_calculate = function(){ //inter media variable var pre_qual_mortgage;//E6, result for showing var max_house_price;//E7, maximum house price //var stopper;//E56,E57,E58 var best_case_mortgage;//E41 best case mortgage amount var best_purchase_price;//E42 best case mortgage purchase price var best_case_mortgage_cal;//calculate principal outstanding before compare downpayment calculation var average;//G52 //var total_weight_average;//L39 var total_weight;//G51 var max_monthly_payment;//E39 var GDS;// Gross Debt Service, Total Allowable Monthly Mortgage Payment E32 var TDS;//Total Debt Service, Total Allowable Monthly Mortgage Payment E35 var lower_DS;//lower of the GDS or TDS E39 var mortgage_base_on_downpayment;//Total Allowable Mortgage based on downpayment E37 var bankruptcyStopper; var averageStopper; var minimumStopper; var total_weight;//G51 var mortgage_by_weight;//E54, Allowable mortgage by weighted average var price_by_weight;//E55, allowable price by weighted average var downPayment_rate; var insurance_rate; var CMHC_price;//E43 --todo var total_allowed_purchase_price;//E44 --- todo getFormValue(); GDS = MINIMUM_REQUIRED_GDS * (annualIncome/12) - (estimatedMonthlyCondoFee + estimatedAnnualTax/12 + HEAT); TDS = MINIMUM_REQUIRED_TDS * (annualIncome/12) - (estimatedMonthlyCondoFee + currentDebts + estimatedAnnualTax/12 + HEAT); lower_DS = (GDS > TDS)?TDS:GDS; mortgage_base_on_downpayment = toCurrency(downPayment/MINIMUM_DOWN_PAYMENT); best_case_mortgage_cal = toCurrency(lower_DS *(1-Math.pow(Math.pow((1+AVERAGE_MORTGAGE_RATE/2),(1/6)),(-12)*AVERAGE_MORTGAGE_AMMORTIZATION))/(Math.pow((1+AVERAGE_MORTGAGE_RATE/2),(1/6))-1)); best_case_mortgage = (best_case_mortgage_cal < mortgage_base_on_downpayment)?best_case_mortgage_cal:mortgage_base_on_downpayment; best_purchase_price = best_case_mortgage/1 + downPayment/1;//no use calculate here //alert("best_case_mortgage_cal: " + best_case_mortgage_cal + " mortgage_base_on_downpayment: " +mortgage_base_on_downpayment + " best_case_mortgage:"+best_case_mortgage); //alert("best_purchase_price: " +best_purchase_price+" downpayment:"+ downPayment); //alert("GDS TDS: " + GDS + " " + TDS); if(best_case_mortgage == 0){ //alert("failed by best_case_mortgage =0"); //pre_qual_mortgage = CANNOT_QUALIFY; //max_house_price = CANNOT_QUALIFY; $("#prequal_mortgage").html("NA"); $("#max_house_Price").html(CANNOT_QUALIFY); $("#monthly_payments").html("NA"); } else{ //alert(workType +"--"+ TYPE_OF_WORK_MULTIPLIER +"--"+ credit+"--"+ CREDIT_MULTIPLIER +"--"+ downpaymentSource +"--"+ DOWNPAYMENT_SOURCE_MULTIPLIER +"--"+ homeType +"--"+ HOME_TYPE_MULTIPLIER); total_weight = workType * TYPE_OF_WORK_MULTIPLIER + credit * CREDIT_MULTIPLIER + downpaymentSource * DOWNPAYMENT_SOURCE_MULTIPLIER + homeType * HOME_TYPE_MULTIPLIER; if(workType*credit*downpaymentSource*homeType==0){ total_weight =0; } average = total_weight/TOTAL_WEIGHT_AVERAGE; //alert("work credit downpayment hometype total_weight average: "+ workType +" " +credit+" "+ downpaymentSource+" " + homeType+" "+total_weight + " " + average); //get the CMHC downPayment_rate = (downPayment/best_case_mortgage)*100; if(downPayment_rate>= downpaymentRates[3]) insurance_rate = insuranceRates[3]; else if(downPayment_rate>= downpaymentRates[2]) insurance_rate = insuranceRates[2]; else if(downPayment_rate>= downpaymentRates[1]) insurance_rate = insuranceRates[1]; else if(downPayment_rate>= downpaymentRates[0]) insurance_rate = insuranceRates[0]; //else won't get here because because we tested this value by mortgage_base_on_downpayment CMHC_price=toCurrency(best_case_mortgage * insurance_rate/100); mortgage_by_weight = best_case_mortgage * average; price_by_weight = mortgage_by_weight/1 + downPayment/1 - CMHC_price; //alert("mortgage_by_weight: " + mortgage_by_weight/1 + " CMHC_price"+ CMHC_price); //calculate 3 stopper bankruptcyStopper = (bankruptcy == 0)?1:0; averageStopper = ((total_weight/TOTAL_WEIGHT_AVERAGE)>MINIMUM_REQUIRED_AVERAGE)?1:0; minimumStopper = (price_by_weight>MINIMUM_LOAN_AMOUNT)?1:0; //alert("price_by_weight minimum_loan_amount stopper(bankruptcy average minimum): " + price_by_weight + " -- " + MINIMUM_LOAN_AMOUNT +" ("+bankruptcyStopper +","+ averageStopper +","+minimumStopper+")"); pre_qual_mortgage = mortgage_by_weight * bankruptcyStopper * averageStopper * minimumStopper; max_house_price = price_by_weight * bankruptcyStopper * averageStopper * minimumStopper; if(pre_qual_mortgage == 0){ //alert("failed by the stopper"); $("#prequal_mortgage").html("NA"); $("#max_house_Price").html(CANNOT_QUALIFY); $("#monthly_payments").html("NA"); } else{ $("#prequal_mortgage").html("$" + toCurrency(pre_qual_mortgage)); $("#max_house_Price").html("$" + toCurrency(max_house_price)); $("#monthly_payments").html("$" + toCurrency(lower_DS * average)); } } } //--------------------------------Math & Formatting Utilities--------------------------------// //The pow() method returns the value of x to the power of y (xy). /* *The toFixed() method rounds the Number to the specified number of decimal places. */ function toCurrency(value){ if(typeof value == "number"){ return new Number(value.toFixed(2)); }else{ return new Number(parseFloat(value).toFixed(2)); } } // event handler for cancel and submit button on the mortgage prequalifier form //goto server controller and send out email $.submitPreQForm = function(){ $.ajax({ type:"GET", url:"listings", data:"pathway=341&submitPreQualifier=true&"+$("#mortgagePreQInfoForm").serialize()+"&"+$("#preQualifierTosForm").serialize(), dataType:"html", error: function(data,error){ alert("submit mortgage preQualifier failed: " + data +" " + error); }, success: function(data){ $("#preQ_container").html(data); }, beforeSend: function(){ //$('#qualifierOverlay').block({ message: 'Loading Qualifier, Please wait...'+' ' }); }, complete: function (XMLHttpRequest, textStatus) { //$('#qualifierOverlay').unblock(); } }); } })();