how to create logical image from plot in a given scale?

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Osama Tabbakh 2019-2-23

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评论： Osama Tabbakh 2019-2-27

I want to transform two vectors (x, y) that describe a straight line in the domain (axis([1e-2 7e-2 1e-2 7e-2])) into a logical matrix.

x = linspace (2e-2,6e-2,20);
y = 4e-2 * ones (1,20);
a = [x' y'];
plot (x,y);
axis([1e-2 7e-2 1e-2 7e-2])

I want to get 100*100 matrix, which describe this plot. For that I can creat zeros matrix and then I have to put the ones in the correct place in this matrix. But I don't know where are the correct places.

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Image Analyst 2019-2-23

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It would just be a line since your y values are all the same:

logImage = true(1, length(y));
imshow(logImage);

Do you have some kind of formula for y?

Osama Tabbakh 2019-2-23

No, y has contant number, because it is a line. But in this way I get a vector. Besides I need a matrix, which hasn't the same size like the vectors, but (100*100).

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Answer 1

Munish Raj 2019-2-27

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https://www.mathworks.com/matlabcentral/answers/446594-how-to-create-logical-image-from-plot-in-a-given-scale

Hello Osama Tabbakh,

Since the line is in the middle of your plot, the row indices of the plot will be the 50th row(middle).

Since the line goes from 0.02 - 0.06 and the axes start from 0.01 and ends at 0.07, your line will start in the 17th position and end at the 83rd position on the x axis.

The following code implements this

im = zeros(100); %Create a 100x100 matrix of zeros 
im(50,17:83)=1 % make the necessary elements  
I = mat2gray(im); 
imshow(I); %Displays the image 

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Munish Raj 2019-2-27

编辑：Munish Raj 2019-2-27

Hello

use your mouse , and drag the corner of the image window to youmake the image as big as tou want it.

Thank you

Osama Tabbakh 2019-2-27

And do u know how i can do that automatically? I have different shape of lines and i dont want every time to calculate the position of the ones on hand.

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