# How do I add local min and max values on each line of the plot like the plot shown below?

조회 수: 10 (최근 30일)
Bryan Tassin 2021년 8월 28일
댓글: TADA 2021년 9월 5일
%Code used for first plot
% Need the first plot to look exactly like the second plot
plot(rad1,'red')
hold on
plot(in,'yellow')
plot(in1,'blue')
plot(in2,'green')
title('Position Analysis')
xlabel('\Theta2(rads)')
ylabel('Outputs')
legend({'\Theta3(radians)','R3(in)','R4(in)','R5(in)'},'FontSize',6)
xticks([0 50 100 150 200 250 300 350 400])
xticklabels({'0','\pi/4','\pi/2','3\pi/4','\pi','5\pi/4','3\pi/2','7\pi/4','2\pi'})
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Ive J 2021년 8월 28일
doc annotation
Bryan Tassin 2021년 8월 28일
can you be a little more specific? what would i write for this particular situation?

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### 채택된 답변

Image Analyst 2021년 9월 5일
If you just have one global peak and valley, try this:
maxValue = max(in);
indexesOfMaxima = find(in == maxValue);
plot(indexesOfMaxima, in(indexesOfMaxima), 'rx', 'LineWidth', 2, 'MarkerSize', 15);
% Repeat for in1 and in2 using their colors.
If you have local mins and maxima, use findpeaks() in the Signal Processing Toolbox
[peakValues, peakIndexes] = findpeaks(in);
[valleyValues, valleyIndexes] = findpeaks(-in); % Turn it upside down then find peaks.
valleyValues = -valleyValues;
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TADA 2021년 9월 5일
Image analysts answer is definitely more complete.

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### 추가 답변 (1개)

TADA 2021년 8월 28일
Im not sure, but it seems to me that the plot you are trying to duplicate marks local minima/maxima points as the absolute minimum/maximum values in each dataset, and not using some more complecated peak analysis.
In that case you can easilly find the deeps and peaks using
x = 1:100;
rad1 = sin(x).^2 .* tan(x);
[localMinValueRad1, localMinIdxRad1] = min(rad1);
[localMaxValueRad1, localMaxIdxRad1] = max(rad1);
plot(rad1, 'red');
hold on;
plot([localMinIdxRad1(:); localMaxIdxRad1(:)], [localMinValueRad1(:); localMaxValueRad1(:)], 'rx');
% continue doing this for the rest of the datasets
##### 댓글 수: 4이전 댓글 2개 표시이전 댓글 2개 숨기기
Bryan Tassin 2021년 9월 5일
it changes the plot completely with the code i am running currently. i just need to add markers at the max and min locations on each line.
TADA 2021년 9월 5일
what do you mean by changes the plot completely?
did you use my code as-is?

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