Programming Forums > Web Development and Design > JavaScript and Client-Side Browser Scripting

MiKuS · Jun 5th, 2007, 11:01 PM

I currently am making a calculator (to learn javascript better)

it's a karvonen heart rate calculator which calculates what your target heart rate BPM should be for a percentage workout, the formula is as follows:

(maximum heart rate = maximum achievable heart rate)
(minimum heart rate = heart rate measured just after waking up)

maximum heart rate - minimum heart rate * workout percentage + minimum heart rate = target bpm

ok, now i can get the formula kinda working.. the poblem i have is with this code:

targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)*percentZoneMin/100)+minHeartRate;

instead of adding minHeartRate it joins it like two strings like 4499 instead of showing 143 (44+99). Below is the code i'm using

(Toggle Plain Text)

function calc(form){
var maxHeartRate;
var minHeartRate;
var percentZoneMin;
var percentZoneMax;
var targetHeartRateLow;
var targetHeartRateHigh;

minHeartRate=form.rest_hr.value;
maxHeartRate=form.max_hr.value;
percentZoneMin=form.percent_zone1.value;
percentZoneMax=form.percent_zone2.value;

targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)*percentZoneMin/100)+minHeartRate;
targetHeartRateHigh=Math.floor((maxHeartRate-minHeartRate)*percentZoneMax/100)+minHeartRate;
form.target_hr1.value=targetHeartRateLow;
form.target_hr2.value=targetHeartRateHigh;

}

Infinite Recursion · Jun 6th, 2007, 8:09 AM

look into using the parseInt function.
(http://www.w3schools.com/jsref/jsref_parseInt.asp)

MiKuS · Jul 9th, 2007, 12:44 AM

it's been a while since i last posted (been busy) but i got it in the end, here is the code i used.

 javascript Syntax (Toggle Plain Text) 
//Work Out Heart Rate Min - Max
function calc(form){
var maxHeartRate;
var minHeartRate;
var percentZoneMin;
var percentZoneMax;
var targetHeartRateLow;
var targetHeartRateHigh;
//Get form values
minHeartRate=parseInt(form.rest_hr.value,10);
maxHeartRate=parseInt(form.max_hr.value,10);
percentZoneMin=form.percent_zone1.value;
percentZoneMax=form.percent_zone2.value;
//Run our calculation
targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)*percentZoneMin/100)+minHeartRate;
targetHeartRateHigh=Math.floor((maxHeartRate-minHeartRate)*percentZoneMax/100)+minHeartRate;
//update our form
form.target_hr1.value=targetHeartRateLow;
form.target_hr2.value=targetHeartRateHigh;
 
}
//Work Out Heart Rate Min - Max
function calc(form){
var maxHeartRate;
var minHeartRate;
var percentZoneMin;
var percentZoneMax;
var targetHeartRateLow;
var targetHeartRateHigh;
//Get form values
minHeartRate=parseInt(form.rest_hr.value,10);
maxHeartRate=parseInt(form.max_hr.value,10);
percentZoneMin=form.percent_zone1.value;
percentZoneMax=form.percent_zone2.value;
//Run our calculation
targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)*percentZoneMin/100)+minHeartRate;
targetHeartRateHigh=Math.floor((maxHeartRate-minHeartRate)*percentZoneMax/100)+minHeartRate;
//update our form
form.target_hr1.value=targetHeartRateLow;
form.target_hr2.value=targetHeartRateHigh;

}

Thanks for the help.

Grich · Sep 23rd, 2007, 6:46 PM

I know it's over, but you could also use the Number() function as well as the parseInt() function.

It brings back a float / double.

Jun 5th, 2007, 11:01 PM	#1
MiKuS Programmer Join Date: Jun 2007 Posts: 93 Rep Power: 2	Help with Calculator I currently am making a calculator (to learn javascript better) it's a karvonen heart rate calculator which calculates what your target heart rate BPM should be for a percentage workout, the formula is as follows: (maximum heart rate = maximum achievable heart rate) (minimum heart rate = heart rate measured just after waking up) maximum heart rate - minimum heart rate * workout percentage + minimum heart rate = target bpm ok, now i can get the formula kinda working.. the poblem i have is with this code: targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)percentZoneMin/100)+minHeartRate; instead of adding minHeartRate it joins it like two strings like 4499 instead of showing 143 (44+99). Below is the code i'm using (Toggle Plain Text) function calc(form){ var maxHeartRate; var minHeartRate; var percentZoneMin; var percentZoneMax; var targetHeartRateLow; var targetHeartRateHigh; minHeartRate=form.rest_hr.value; maxHeartRate=form.max_hr.value; percentZoneMin=form.percent_zone1.value; percentZoneMax=form.percent_zone2.value; targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)percentZoneMin/100)+minHeartRate; targetHeartRateHigh=Math.floor((maxHeartRate-minHeartRate)percentZoneMax/100)+minHeartRate; form.target_hr1.value=targetHeartRateLow; form.target_hr2.value=targetHeartRateHigh; } function calc(form){ var maxHeartRate; var minHeartRate; var percentZoneMin; var percentZoneMax; var targetHeartRateLow; var targetHeartRateHigh; minHeartRate=form.rest_hr.value; maxHeartRate=form.max_hr.value; percentZoneMin=form.percent_zone1.value; percentZoneMax=form.percent_zone2.value; targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)percentZoneMin/100)+minHeartRate; targetHeartRateHigh=Math.floor((maxHeartRate-minHeartRate)*percentZoneMax/100)+minHeartRate; form.target_hr1.value=targetHeartRateLow; form.target_hr2.value=targetHeartRateHigh; }

Jun 6th, 2007, 8:09 AM	#2
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,467 Rep Power: 8	look into using the parseInt function. (http://www.w3schools.com/jsref/jsref_parseInt.asp) __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Jul 9th, 2007, 12:44 AM	#3
MiKuS Programmer Join Date: Jun 2007 Posts: 93 Rep Power: 2	it's been a while since i last posted (been busy) but i got it in the end, here is the code i used. javascript Syntax (Toggle Plain Text) //Work Out Heart Rate Min - Max function calc(form){ var maxHeartRate; var minHeartRate; var percentZoneMin; var percentZoneMax; var targetHeartRateLow; var targetHeartRateHigh; //Get form values minHeartRate=parseInt(form.rest_hr.value,10); maxHeartRate=parseInt(form.max_hr.value,10); percentZoneMin=form.percent_zone1.value; percentZoneMax=form.percent_zone2.value; //Run our calculation targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)percentZoneMin/100)+minHeartRate; targetHeartRateHigh=Math.floor((maxHeartRate-minHeartRate)percentZoneMax/100)+minHeartRate; //update our form form.target_hr1.value=targetHeartRateLow; form.target_hr2.value=targetHeartRateHigh; } //Work Out Heart Rate Min - Max function calc(form){ var maxHeartRate; var minHeartRate; var percentZoneMin; var percentZoneMax; var targetHeartRateLow; var targetHeartRateHigh; //Get form values minHeartRate=parseInt(form.rest_hr.value,10); maxHeartRate=parseInt(form.max_hr.value,10); percentZoneMin=form.percent_zone1.value; percentZoneMax=form.percent_zone2.value; //Run our calculation targetHeartRateLow=Math.floor((maxHeartRate-minHeartRate)percentZoneMin/100)+minHeartRate; targetHeartRateHigh=Math.floor((maxHeartRate-minHeartRate)percentZoneMax/100)+minHeartRate; //update our form form.target_hr1.value=targetHeartRateLow; form.target_hr2.value=targetHeartRateHigh; } Thanks for the help. Last edited by MiKuS; Jul 9th, 2007 at 12:57 AM. Reason: turned on syntax highlighting

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[vbasic] Calculator	dwizzle13	Existing Project Development	13	Oct 12th, 2006 5:44 PM
Programming video game to TI calculator?	magus57	Project Ideas	20	May 5th, 2006 10:19 PM
Calculator Multiple Operations?	jl13	C#	5	Oct 12th, 2005 4:32 PM
Javascript calculator	narroweyes	JavaScript and Client-Side Browser Scripting	7	Jul 30th, 2005 12:46 PM
simple calculator	Jessehk	Show Off Your Open Source Projects	4	May 25th, 2005 4:39 PM

Sep 23rd, 2007, 6:46 PM	#4
Grich Hobbyist Programmer Join Date: Sep 2007 Location: Sydney - Australia Posts: 150 Rep Power: 1	I know it's over, but you could also use the Number() function as well as the parseInt() function. It brings back a float / double.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Programming Forums > Web Development and Design > JavaScript and Client-Side Browser Scripting

Help with Calculator