How do I get object data from a FIG file, such as X and Y data?

i search on matlab searching question but not found it.

I have a graph with a curve. I want to know the Y value from my graph

example X = 10

how to find Y?

thx.

[MRR]

%example  
X = 1:0.1:20;
Y = sin(X);
index = find(X==10);
Y_point = Y(index)    
% See graphically    
plot(X,Y,X(index),Y_point,'o');

[uncung fgv]

not this what i man, i have no X, Y data. I only have hiperbolic curve in matlab graph/file.

[GS76]

Thank you MRR!

Your reply helped me greatly.

Much appreciated.

[afiq hassan]

But what if I want to find x values using y axis?

Answer 1

[Julian Laackmann]

Open the figure using “openfig” and return the “Figure” object as an output argument, such as "fig". Then use “fig” to access the underlying objects in the figure.

 fig = openfig('MySavedPlot.fig')

For example, if the figure contains a line plot, you might want to get the X and Y data for the line. You can get the X and Y data using the XData and YData properties of the "Line" object. You can access the "Line" object through the "Children" property of the axes. You can access the "Axes" object through the “Children” property of the figure.

ax = fig.Children
ln = ax.Children;
X = ln.XData;
Y = ln.YData;

[uncung fgv]

my plot in matlab file. actually the curve is hyperbolic. X data is heigh

Y is velocity

so I want to find E=1/2 mv^2.

I have m data it is ok to find one by one Y data. by using Data Cursor. I want find many Y data from this plot.

[uncung fgv]

i mean how to get data from figure file.

[Image Analyst]

So all you have is a .fig file with the saved figure? You have absolutely no way to get the original data that was plotted to make the figure? There are submissions in the File Exchange to help you digitize values off a picture, such as http://www.mathworks.com/matlabcentral/fileexchange/36904-matlab-script-for-digitizing-a-published-graph

Answer 2

[uncung fgv]

Thx, guys, i already find it on this:

http://www.mathworks.nl/matlabcentral/newsreader/view_thread/249507

http://www.mathworks.de/help/techdoc/ref/openfig.html

Answer 3

[asma chaudhry]

Use Matlab's data cursor to find the first intersection of the line y=x with the graph of y=tan(x) in the first quadrant. Enter your answer as a decimal with 3 decimal places