Question about finding y value for certain x value of a plot

Hello, I have a question about data cursor. My data plot gives me a data cursor which goes by 0.5 for the x-axis values.

For example, when i move the curse right side, it goes like 0.5, 1.0, 1.5, 2.0...

Say I want to know the y-value at the x-value of 5.1

I guess the most simple way is to zoom in and see the value, but there are about 1 thousand data to work with.

Therefore, I want to give a commend that orders to give the y-value at certain x-value. If there isn't a data set, it would be nice to get the value of how the plot line is drawn for the points...(interpolation etc..)

How can I do that?

Answer 1

[Ilham Hardy]

If you have your plot data,

desiredY = interp1(yourXaxisdata,yourYaxisdata,certainX);

[yc j]

OMG!!! this is amazing!!!!!!!!!! Thank you so much!

One more question, How can I get 'desiredY' for decimal to say.. 8?

For example, it's giving me the rounded disiredY value of 0.0042, not 0.0041882

[Stephen23]

 format longg

MATLAB displays to four decimal places by default, but using the command format you can change how values are displayed. Read that link I gave, have a look at some of the possible format options (there is a table at the bottom), and try some with your data.

[yc j]

thank you very much!! this means a lot to me!!

[SANGEERTH P]

Thank you sir.

this works and is amazing

[Joao Gocan]

That solves my problem! Thank you!

[Feroz Mulani]

If i want to find a value say e.g value of x at function y = 1, then how should i write.

[Sara Nasir]

You can interchange x and y in the interp1 command to get the desired output values.

[Florina-Iuliana TUDOR]

Hi, I have kind of the same problem, i made a plot using excel data and i want to see the y value for some x values that are not from the data tabel, how can i do that?

[Torsten]

If X and Y are your data arrays and Xq are your query points, use

Yq = interp1(X,Y,Xq);

[Ganesh P. Prajapat]

Yas, it works perfectly. Thnak you