MATLAB Answers


Need to find the value of x_?, where x_? is x at y=?......

Asked by Ara
on 29 Apr 2013

Dear All,

Just a simple question, I need to find x_15, where x_15 is x at y=15. Please imagine x and y as below,

x       y
0.1     20 
0.05    15
0.2     85 

Thank you!




No products are associated with this question.

1 Answer

Answer by Iman Ansari
on 29 Apr 2013
 Accepted answer


x=[0.1; 0.05; 0.2];
y=[20; 15; 85];


on 29 Apr 2013

Two columns (5357x1 double)like the example x and y. Usually Matlab give me an error but I never faced this problem (no error, no figure..)it's weird. When I plot (el1nov,s4_01nov)the figure show me values for el1nov=15 so I am wondering why can not show me for exact value I want.

Iman Ansari
on 29 Apr 2013

See this works:

s4_01nov=rand([5357 1]);
el1nov=randi(20,[5357 1]);

but with for example 30, because el1nov doesn't have 30 nothing happened. With nnz(el1nov==15) you can check how many 15 in the el1nov vector:

on 29 Apr 2013

Thank you, yes this works. Ok, now by using "nnz" I realize at that value the vector was zero which is not reasonable based on my observation then I will go to recheck that part. So no wonder then why Matlab shows no figure.

Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi test

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

MATLAB Academy

New to MATLAB?

Learn MATLAB today!