Adding text to the plot values in the plot

Hi..Am plotting the different values of slopes of lines in a single plot .But I want to indicate each plotted value with the respective line number how can I do this.. previously I am storing slope values in slope(K).. then am using

for k=1:n
 plot(slope,'*')
 end

Can someone suggest about this...

[Image Analyst]

Why do you need/want the for loop? The plot function call will plot the whole thing - the whole slope array. You're just plotting the whole thing n times.

Answer 1

[Walter Roberson]

Either use legend(), or text() a label in place somewhere along the line.

[Gova ReDDy]

By using legend I tried.

But I was able to plot line joining the points.But how can I denote the points with line number.

can you please tell me this..

[Walter Roberson]

for k=1:n

text(x(k),y(k),num2str(k));

end

[Gova ReDDy]

Danx....

Bt when am using this

if (ycoord && xcoord >=0)

Then am getting error like this

"operands to the && operators must be convertible to logical scalar values"

[Walter Roberson]

Insufficient information. Your previous code did not show any ycoord or xcoord, and you did not show what you want to do in the situation where the test is true, so I am not able to recommend a solution.

The error you see is consistent with ycoord or xcoord not being scalars. The && operator can only be used with scalars.

Note by the way that your code is equivalent to

if (ycoord ~= 0 && xcoord >=0)

[Gova ReDDy]

Sorry...My code is this

Calculating coordinates for multiple Images

[ycoord,xcoord]=find(Image);

if ((ycoord)>0 &&(xcoord) >0)

calculating slope(k);

else

slope(K)=0;

end;

[Walter Roberson]

It is not possible for find() to return 0 or negative coordinates. If it does not find anything, then it returns empty arrays.

find() will, in general, return more than one location. It is not obvious from your code what you want to do with those multiple locations in order to calculate a single slope ?

[Gova ReDDy]

When there is a output(x,y coord) from find() i.e., when there is a line in the current frame of video then it is calculating the slope.

But when there is no line in the current frame of the video then I have to make that frame slope as zero So,how can I make this..

[Walter Roberson]

isempty() can tell you whether there was a result from find() or not.

But again, what if there were (say) 5 values found?

[Gova ReDDy]

Am plotting the "slope" value against "frames".

for k = 1 :240 %no.of frames

%Here in loop am extracting the line from each frame then

[ycoord,xcoord]=find(line);%finding the coordinates of line

Ymax(k)=max(ycoord);

Ymin(k)=min(ycoord);

Xmax(k)=max(xcoord);

Xmin(k)=min(xcoord);

slope(k)=(Ymax(k)-Ymin(k)/Xmax(k)-Xmin(k));%slope=y2-y1/x2-x1

end;

plot(slope,'-ro');%plotting slope values of frames

xlabel('Fame number');

ylabel('SLOPE Of Line In the Frame ');

title('SLOPE PLOT of the VIDEO');

when there is no line in the next frame then the slope value should be zero..

else it should calculate the slope value .

Answer 2

[Gova ReDDy]

This is working

    if((isempty(xcoord)=1) && (isempty(xcoord)=1))
     then
    caluclate slope
    else
     slope=0;
    end