Math Formula - mapping large range to smaller range of numbers

[OptionsOptionsOptions]

I am looking for the math formula to map a large range of numbers to smaller range. Example:

• Old range: 0-270
• New range: 0-100

Thanks

 

[Turveyd]

New = Old / 2.7 ??

Too simple, need more info maybe.

 

[OptionsOptionsOptions]

New = Old / 2.7 ??

Too simple, need more info maybe.

• A = 0
• B = 270
• X = input (example 73)

• C = 0
• D = 100
• Y = output ??????

What is Y?
I'm looking for the math formula.

 

[Turveyd]

Y = 73 / 2.7 = 27.03

Or X / B = 73 / 270 = ( .2703 * 100 ) or 27.03%

D being 100, makes it easy as it's just a percent.

If D = 50 then 73 / 5.4

 

[keesa]

Y=X(D-C)/(B-A)

 

[OptionsOptionsOptions]

Thanks ,but the formula doesn't work. I came up with a new example and tried keesa's formula.

A = 124
B = 970
X = 124 (input)

Mapped to:

C = 0
D = 100
Y = 14.66 (output)

Y output should be 0, but it comes up as 14.66.

 

[2rosy]

standardize your input list from 0 to 1 and then multiply that by
(max_newrange-min_newrange) +min_newrange

input_list=124, 345, 654, 784, 970
std = (input_list - min(input_list)) / ( max(input_list) - min(input_list))
std *( 10-1 )+1

output_list mapped from 1 to 10
1. , 3.35106383, 6.63829787, 8.0212766 , 10.

 

[xandman]

Y=(X-A)/(B-A) where C,D is 0,100. Change the values of C and D and you have to solve for a system of linear equations.

 

[Sekiyo]

a0=140; a1=970;
b0=0; b1=100;

y=(x-a0)/(a1-a0)*(b1-b0)+b0

for a0 < x < a1 and b0 < y <b1

if x= 140 then y= 0
if x=555 then y = 50
if x= 970 then y= 100

Edit: doesn't work yet ... 2s
Corrected

a0=140; a1=970;
b0=100; b1=200;

if x= 555 then y=150

 

[ph1l]

The secret is out.
https://www.ajdesigner.com/phpinterpolation/linear_interpoolation_equation.php