How to get Y value from exponential function that starts at 0,0 and ends at 100,1000











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2
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It's been a while since my math classes so here's the question, any help is appreciated.



I'll be implementing the function in javascript also.



I have an X range of 0-100 and a set max Y of 10000 (which may change).
This is an exponential function and the closer X is to 100, the closer it gets to Y max and x=100 is y=10000. So my question is, what is the function that can handle this? Ideally I'd like to have something to control the steepness of the curve as well.



What I have in mind :
graph



Thanks.










share|improve this question
























  • Do you want to know how to get the Y value in javascript?
    – Donny Verduijn
    Nov 10 at 22:36










  • Yeah, or just the expression, I can manage putting it in js from there. Whatever is easiest for you.
    – LAZ
    Nov 10 at 22:38






  • 1




    Because otherwise, this question should be asked on math.stackexchange.com
    – Donny Verduijn
    Nov 10 at 22:40










  • Well it will be used in javascript
    – LAZ
    Nov 10 at 22:43










  • Programming goes hand to wand with maths, thus this is really just a math question... this indeed should be asked on math.stackexchange.com
    – Akxe
    Nov 11 at 1:57















up vote
2
down vote

favorite












It's been a while since my math classes so here's the question, any help is appreciated.



I'll be implementing the function in javascript also.



I have an X range of 0-100 and a set max Y of 10000 (which may change).
This is an exponential function and the closer X is to 100, the closer it gets to Y max and x=100 is y=10000. So my question is, what is the function that can handle this? Ideally I'd like to have something to control the steepness of the curve as well.



What I have in mind :
graph



Thanks.










share|improve this question
























  • Do you want to know how to get the Y value in javascript?
    – Donny Verduijn
    Nov 10 at 22:36










  • Yeah, or just the expression, I can manage putting it in js from there. Whatever is easiest for you.
    – LAZ
    Nov 10 at 22:38






  • 1




    Because otherwise, this question should be asked on math.stackexchange.com
    – Donny Verduijn
    Nov 10 at 22:40










  • Well it will be used in javascript
    – LAZ
    Nov 10 at 22:43










  • Programming goes hand to wand with maths, thus this is really just a math question... this indeed should be asked on math.stackexchange.com
    – Akxe
    Nov 11 at 1:57













up vote
2
down vote

favorite









up vote
2
down vote

favorite











It's been a while since my math classes so here's the question, any help is appreciated.



I'll be implementing the function in javascript also.



I have an X range of 0-100 and a set max Y of 10000 (which may change).
This is an exponential function and the closer X is to 100, the closer it gets to Y max and x=100 is y=10000. So my question is, what is the function that can handle this? Ideally I'd like to have something to control the steepness of the curve as well.



What I have in mind :
graph



Thanks.










share|improve this question















It's been a while since my math classes so here's the question, any help is appreciated.



I'll be implementing the function in javascript also.



I have an X range of 0-100 and a set max Y of 10000 (which may change).
This is an exponential function and the closer X is to 100, the closer it gets to Y max and x=100 is y=10000. So my question is, what is the function that can handle this? Ideally I'd like to have something to control the steepness of the curve as well.



What I have in mind :
graph



Thanks.







javascript function math graph linear-algebra






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 10 at 22:27

























asked Nov 10 at 22:11









LAZ

385




385












  • Do you want to know how to get the Y value in javascript?
    – Donny Verduijn
    Nov 10 at 22:36










  • Yeah, or just the expression, I can manage putting it in js from there. Whatever is easiest for you.
    – LAZ
    Nov 10 at 22:38






  • 1




    Because otherwise, this question should be asked on math.stackexchange.com
    – Donny Verduijn
    Nov 10 at 22:40










  • Well it will be used in javascript
    – LAZ
    Nov 10 at 22:43










  • Programming goes hand to wand with maths, thus this is really just a math question... this indeed should be asked on math.stackexchange.com
    – Akxe
    Nov 11 at 1:57


















  • Do you want to know how to get the Y value in javascript?
    – Donny Verduijn
    Nov 10 at 22:36










  • Yeah, or just the expression, I can manage putting it in js from there. Whatever is easiest for you.
    – LAZ
    Nov 10 at 22:38






  • 1




    Because otherwise, this question should be asked on math.stackexchange.com
    – Donny Verduijn
    Nov 10 at 22:40










  • Well it will be used in javascript
    – LAZ
    Nov 10 at 22:43










  • Programming goes hand to wand with maths, thus this is really just a math question... this indeed should be asked on math.stackexchange.com
    – Akxe
    Nov 11 at 1:57
















Do you want to know how to get the Y value in javascript?
– Donny Verduijn
Nov 10 at 22:36




Do you want to know how to get the Y value in javascript?
– Donny Verduijn
Nov 10 at 22:36












Yeah, or just the expression, I can manage putting it in js from there. Whatever is easiest for you.
– LAZ
Nov 10 at 22:38




Yeah, or just the expression, I can manage putting it in js from there. Whatever is easiest for you.
– LAZ
Nov 10 at 22:38




1




1




Because otherwise, this question should be asked on math.stackexchange.com
– Donny Verduijn
Nov 10 at 22:40




Because otherwise, this question should be asked on math.stackexchange.com
– Donny Verduijn
Nov 10 at 22:40












Well it will be used in javascript
– LAZ
Nov 10 at 22:43




Well it will be used in javascript
– LAZ
Nov 10 at 22:43












Programming goes hand to wand with maths, thus this is really just a math question... this indeed should be asked on math.stackexchange.com
– Akxe
Nov 11 at 1:57




Programming goes hand to wand with maths, thus this is really just a math question... this indeed should be asked on math.stackexchange.com
– Akxe
Nov 11 at 1:57












1 Answer
1






active

oldest

votes

















up vote
1
down vote



accepted










The formula would be a variant of y = a * exp(b * x), where you can play around with a and b to get the curve / endpoints you want. For 100/100.000, you could use:
y = 5 * exp(0.0990348754944493 * x). In Javascript that would look something like:



function getExponent(x) {
return 5 * Math.pow(0.0990348754944493*x);
}


or if you want a and b to be variables:



function getExponent(x,a,b) {
return a * Math.pow(b*x);
}





share|improve this answer























  • I want to be able to provide x and the y value at x=100. I can't go in the code and edit the floats every time I have a different y max. For example, what is Y when X = 56 when the exponential starts at (0,0) and intercepts with the point (100,10000)? The range of 0-100 will never change, the steepness I will play with but eventually will be static and the "max" Y value will vary. Think of it like a slider, you slide it up to the max which in this case is 10000. But some sliders go up to 100000 or a million, etc.
    – LAZ
    Nov 11 at 2:53










  • If you want to make the steepness static, we can assume b is (becomes) fixed. Since y_max and x_max are known (although y_max is varying), you can use a function to calculate a: a = exp(b * x_max) / y_max = exp(b * 100) / y_max Then... whenever you have fixed b, the interceptions (0,0) and (100, y_max) will always hold.
    – CIAndrews
    Nov 11 at 3:20










  • Thanks, makes sense but Math.pow() requires two args, and exp() doesn't exist in my environment. I did try Math.exp(b * x_max) / y_max but that returns an 18 digit number.
    – LAZ
    Nov 11 at 3:53












  • Ah yes, my b was incorrect. Changed it to 0.0990348754944493, that results exactly in y = 100.000 for x = 100 and a = 5
    – CIAndrews
    Nov 11 at 4:18











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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
1
down vote



accepted










The formula would be a variant of y = a * exp(b * x), where you can play around with a and b to get the curve / endpoints you want. For 100/100.000, you could use:
y = 5 * exp(0.0990348754944493 * x). In Javascript that would look something like:



function getExponent(x) {
return 5 * Math.pow(0.0990348754944493*x);
}


or if you want a and b to be variables:



function getExponent(x,a,b) {
return a * Math.pow(b*x);
}





share|improve this answer























  • I want to be able to provide x and the y value at x=100. I can't go in the code and edit the floats every time I have a different y max. For example, what is Y when X = 56 when the exponential starts at (0,0) and intercepts with the point (100,10000)? The range of 0-100 will never change, the steepness I will play with but eventually will be static and the "max" Y value will vary. Think of it like a slider, you slide it up to the max which in this case is 10000. But some sliders go up to 100000 or a million, etc.
    – LAZ
    Nov 11 at 2:53










  • If you want to make the steepness static, we can assume b is (becomes) fixed. Since y_max and x_max are known (although y_max is varying), you can use a function to calculate a: a = exp(b * x_max) / y_max = exp(b * 100) / y_max Then... whenever you have fixed b, the interceptions (0,0) and (100, y_max) will always hold.
    – CIAndrews
    Nov 11 at 3:20










  • Thanks, makes sense but Math.pow() requires two args, and exp() doesn't exist in my environment. I did try Math.exp(b * x_max) / y_max but that returns an 18 digit number.
    – LAZ
    Nov 11 at 3:53












  • Ah yes, my b was incorrect. Changed it to 0.0990348754944493, that results exactly in y = 100.000 for x = 100 and a = 5
    – CIAndrews
    Nov 11 at 4:18















up vote
1
down vote



accepted










The formula would be a variant of y = a * exp(b * x), where you can play around with a and b to get the curve / endpoints you want. For 100/100.000, you could use:
y = 5 * exp(0.0990348754944493 * x). In Javascript that would look something like:



function getExponent(x) {
return 5 * Math.pow(0.0990348754944493*x);
}


or if you want a and b to be variables:



function getExponent(x,a,b) {
return a * Math.pow(b*x);
}





share|improve this answer























  • I want to be able to provide x and the y value at x=100. I can't go in the code and edit the floats every time I have a different y max. For example, what is Y when X = 56 when the exponential starts at (0,0) and intercepts with the point (100,10000)? The range of 0-100 will never change, the steepness I will play with but eventually will be static and the "max" Y value will vary. Think of it like a slider, you slide it up to the max which in this case is 10000. But some sliders go up to 100000 or a million, etc.
    – LAZ
    Nov 11 at 2:53










  • If you want to make the steepness static, we can assume b is (becomes) fixed. Since y_max and x_max are known (although y_max is varying), you can use a function to calculate a: a = exp(b * x_max) / y_max = exp(b * 100) / y_max Then... whenever you have fixed b, the interceptions (0,0) and (100, y_max) will always hold.
    – CIAndrews
    Nov 11 at 3:20










  • Thanks, makes sense but Math.pow() requires two args, and exp() doesn't exist in my environment. I did try Math.exp(b * x_max) / y_max but that returns an 18 digit number.
    – LAZ
    Nov 11 at 3:53












  • Ah yes, my b was incorrect. Changed it to 0.0990348754944493, that results exactly in y = 100.000 for x = 100 and a = 5
    – CIAndrews
    Nov 11 at 4:18













up vote
1
down vote



accepted







up vote
1
down vote



accepted






The formula would be a variant of y = a * exp(b * x), where you can play around with a and b to get the curve / endpoints you want. For 100/100.000, you could use:
y = 5 * exp(0.0990348754944493 * x). In Javascript that would look something like:



function getExponent(x) {
return 5 * Math.pow(0.0990348754944493*x);
}


or if you want a and b to be variables:



function getExponent(x,a,b) {
return a * Math.pow(b*x);
}





share|improve this answer














The formula would be a variant of y = a * exp(b * x), where you can play around with a and b to get the curve / endpoints you want. For 100/100.000, you could use:
y = 5 * exp(0.0990348754944493 * x). In Javascript that would look something like:



function getExponent(x) {
return 5 * Math.pow(0.0990348754944493*x);
}


or if you want a and b to be variables:



function getExponent(x,a,b) {
return a * Math.pow(b*x);
}






share|improve this answer














share|improve this answer



share|improve this answer








edited Nov 11 at 4:18

























answered Nov 11 at 1:48









CIAndrews

1766




1766












  • I want to be able to provide x and the y value at x=100. I can't go in the code and edit the floats every time I have a different y max. For example, what is Y when X = 56 when the exponential starts at (0,0) and intercepts with the point (100,10000)? The range of 0-100 will never change, the steepness I will play with but eventually will be static and the "max" Y value will vary. Think of it like a slider, you slide it up to the max which in this case is 10000. But some sliders go up to 100000 or a million, etc.
    – LAZ
    Nov 11 at 2:53










  • If you want to make the steepness static, we can assume b is (becomes) fixed. Since y_max and x_max are known (although y_max is varying), you can use a function to calculate a: a = exp(b * x_max) / y_max = exp(b * 100) / y_max Then... whenever you have fixed b, the interceptions (0,0) and (100, y_max) will always hold.
    – CIAndrews
    Nov 11 at 3:20










  • Thanks, makes sense but Math.pow() requires two args, and exp() doesn't exist in my environment. I did try Math.exp(b * x_max) / y_max but that returns an 18 digit number.
    – LAZ
    Nov 11 at 3:53












  • Ah yes, my b was incorrect. Changed it to 0.0990348754944493, that results exactly in y = 100.000 for x = 100 and a = 5
    – CIAndrews
    Nov 11 at 4:18


















  • I want to be able to provide x and the y value at x=100. I can't go in the code and edit the floats every time I have a different y max. For example, what is Y when X = 56 when the exponential starts at (0,0) and intercepts with the point (100,10000)? The range of 0-100 will never change, the steepness I will play with but eventually will be static and the "max" Y value will vary. Think of it like a slider, you slide it up to the max which in this case is 10000. But some sliders go up to 100000 or a million, etc.
    – LAZ
    Nov 11 at 2:53










  • If you want to make the steepness static, we can assume b is (becomes) fixed. Since y_max and x_max are known (although y_max is varying), you can use a function to calculate a: a = exp(b * x_max) / y_max = exp(b * 100) / y_max Then... whenever you have fixed b, the interceptions (0,0) and (100, y_max) will always hold.
    – CIAndrews
    Nov 11 at 3:20










  • Thanks, makes sense but Math.pow() requires two args, and exp() doesn't exist in my environment. I did try Math.exp(b * x_max) / y_max but that returns an 18 digit number.
    – LAZ
    Nov 11 at 3:53












  • Ah yes, my b was incorrect. Changed it to 0.0990348754944493, that results exactly in y = 100.000 for x = 100 and a = 5
    – CIAndrews
    Nov 11 at 4:18
















I want to be able to provide x and the y value at x=100. I can't go in the code and edit the floats every time I have a different y max. For example, what is Y when X = 56 when the exponential starts at (0,0) and intercepts with the point (100,10000)? The range of 0-100 will never change, the steepness I will play with but eventually will be static and the "max" Y value will vary. Think of it like a slider, you slide it up to the max which in this case is 10000. But some sliders go up to 100000 or a million, etc.
– LAZ
Nov 11 at 2:53




I want to be able to provide x and the y value at x=100. I can't go in the code and edit the floats every time I have a different y max. For example, what is Y when X = 56 when the exponential starts at (0,0) and intercepts with the point (100,10000)? The range of 0-100 will never change, the steepness I will play with but eventually will be static and the "max" Y value will vary. Think of it like a slider, you slide it up to the max which in this case is 10000. But some sliders go up to 100000 or a million, etc.
– LAZ
Nov 11 at 2:53












If you want to make the steepness static, we can assume b is (becomes) fixed. Since y_max and x_max are known (although y_max is varying), you can use a function to calculate a: a = exp(b * x_max) / y_max = exp(b * 100) / y_max Then... whenever you have fixed b, the interceptions (0,0) and (100, y_max) will always hold.
– CIAndrews
Nov 11 at 3:20




If you want to make the steepness static, we can assume b is (becomes) fixed. Since y_max and x_max are known (although y_max is varying), you can use a function to calculate a: a = exp(b * x_max) / y_max = exp(b * 100) / y_max Then... whenever you have fixed b, the interceptions (0,0) and (100, y_max) will always hold.
– CIAndrews
Nov 11 at 3:20












Thanks, makes sense but Math.pow() requires two args, and exp() doesn't exist in my environment. I did try Math.exp(b * x_max) / y_max but that returns an 18 digit number.
– LAZ
Nov 11 at 3:53






Thanks, makes sense but Math.pow() requires two args, and exp() doesn't exist in my environment. I did try Math.exp(b * x_max) / y_max but that returns an 18 digit number.
– LAZ
Nov 11 at 3:53














Ah yes, my b was incorrect. Changed it to 0.0990348754944493, that results exactly in y = 100.000 for x = 100 and a = 5
– CIAndrews
Nov 11 at 4:18




Ah yes, my b was incorrect. Changed it to 0.0990348754944493, that results exactly in y = 100.000 for x = 100 and a = 5
– CIAndrews
Nov 11 at 4:18


















 

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