Message Boards Message Boards

GROUPS:

Change variables with factors while keeping axes the same?

Posted 1 month ago
282 Views
|
3 Replies
|
1 Total Likes
|

Dear Community,

I am not that familiar with Mathematica and therefore I do not know if this is an easy question. I have a very complex formula including two variables z= x and y. In this formula, I want that everywhere where there is x, a 2 multiplied to this (2•x) and everywhere where there is y, 3•y. This goes well until I 3D plot this and my axes take the factor (2 and 3) into account. I want my axes to be x,y,z and not 2x,3y,z. Dividing my axes does not work --> (Plot3D[%87, {x/2, 0, 2}, {y/3, 0, 2}], which seemed logical to me. I don't know how to fix this and I could not find anything on the internet. Therefore my question. Hopefully someone can help me. :)

Kind regards, J.

POSTED BY: JT V
Answer
3 Replies
Posted 1 month ago

You have f(x,y)=a very complex formula, say

F(x_,y_):=BesselI(1,x)+Sin[x]*BesselY(2,y)

just for the sake of explicitness. Plot3D accepts a scalar function of two variables, in this case x and y, and a region to plot them.

But what do you mean to stretch (or shrink) the z axis by a factor of 3? z is the dependent variable.

Posted 1 month ago

I am sorry for my confusing use of symbols. Indeed, I have a z=f(x,y) function where I want to increase x and y with a certain number (2x and 3y). In my research, x and y are increasing with a percentage and I want to see what the difference is between two plots; one where I include the percentual multiplication and one where I don't. However, since my axes take over this percentage, my two graphs are the same (which is the problem).

POSTED BY: JT V
Answer
Posted 1 month ago

I have fixed my problem in Matlab for 2D. It was easier for me to solve the 3D linear equations in Mathematica and plot it. Here is my (real complex) problem in 2D in Matlab. Here you can see that whenever I use p1/p2/p3/p4/p5 as my x-axis, my two graphs are similar, while if I just use my original p (a/b, without percentage multiplication), the graphs differ (which is what I want). However, my equations are now SO difficult that it's not an easy job for me to do the percentages manually in the equations, as I did in Matlab with 2D.

enter image description here![ ][2]enter image description here

POSTED BY: JT V
Answer
Reply to this discussion
Community posts can be styled and formatted using the Markdown syntax.
Reply Preview
Attachments
Remove
or Discard

Group Abstract Group Abstract