How to find the C=corresponding x axis values of a peak on Y-axis?

I have to find the 'x' values at which the peak is maximum. How can I find that? Please help.

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    11371.8 11390.4 11402.2 11387.3 11387.6 11387.3 11394.4 11447.1 11465 11431.5 11457.1 11460.6 11485.7 11491 11458.5 11440.9 11434.8 11454.9 11453.5 11463 11446.3 11475.9 11482.5 11457.3 11454.8 11445 11442.8 11440.9 11386.9 11412.6 11387.1 11402 11376.8 11425.7 11426 11426.7 11421.5 11438.4 11455.1 11423 11450 11429.3 11486 11504.3 11494.1 11510.8 11527.5 11562.5 11570.8 11520.7 11496.2 11508.6 11514.3 11457.7 11457.8 11435.8 11465 11475.5 11459.7 11462.8 11452.2 11499.4 11508 11478.9 11483.9 11479.6 11493.1 11451.4 11421.4 11366.3 11389.8 11385 11339.1 11322.4 11336.5 11346.9 11315.2 11328.6 11323 11348.3 11351.3 11346.5 11369.6 11400.5 11426.4 11432.4 11404.5 11415 11428.9 11446.8 11408.2 11417.9 11379.6 11379.4 11411 11383.2 11409.2 11443.8 11453.7 11455.9...      
    11420.4 11392.9 11395.4 11389.9 11358.4 11370.3 11404.4 11406 11418.9 11404.7 11460.1 11472.4 11510.2 11472 11457.3 11493.7 11507.3 11512.8 11489.1 11481.3 11481.6 11451.9 11423.8 11336.1 11413.5 11412.1 11376.1 11368.6 11371.8 11361.7 11320.5 11294.2 11268.4 11302.5 11344.5 11320.8 11345.4 11308.4 11327.4 11337.9 11340 11354.1 11355.1 11376.6 11406.4 11422.9 11434.4 11441.6 11457.7 11474.1 11487.9 11489.5 11461.2 11477.4 11464.9 11506.4 11484.7 11476.8 11466.2 11746 11060.5 11805 11714 11676.6 11674.9 11609.2 11516.9 11505 11534.9 11527.1 11514.4 11513.6 11535.7 11450 11435.1 11390.1 11426.6 11406 11385.3 11359.2 11332.5 11327.7 11302.2 11296.2 11267 11269.5 11246.4 11260.3 11284.6 11268.1 11257.5 11258.9 11252.8 11259.1 11304.2 11286.2 11319.8 11441.8 11558.1 11648.4...      
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    11448.8 11449.7 11442.1 11424.9 11409.3 11402.4 11386.8 11413.2 11434.9 11447.9 11441.4 11434.9 11405.2 11414.3 11416.5 11437.9 11455.2 11404.8 11422.6 11435.6 11424.7 11457.5 11439 11442.2 11398.3 11381 11424.2 11421.2 11391 11390.9 11384.8 11402 11396.7 11382.7 11388.9 11357.5 11377.2 11353.7 11334.6 11346.5 11335.4 11330.6 11321 11329.2 11354.6 11369.8 11361 11363 11355.9 11399.1 11394 11410.7 11394 11405.1 11407.4 11399.2 11438 11435.8 11429.7 11419.8 11387.2 11375.3 11381.1 11381.3 11397.8 11383.4 11364.6 11332.7 11317 11345.3 11322 11359.8 11337.2 11331.4 11319.2 11321.3 11325 11334.7 11360.3 11356 11337.7 11343.6 11353.7 11379.3 11436.6 11428.2 11437.8 11411.4 11438.8 11461.5 11468.5 11489.3 11459.3 11437.7 11415.6 11398.6 11418.8 11415.6 11394.3 11380 ...       
    11365.9 11366.6 11369.4 11386.2 11405.7 11349 11372.3 11370.5 11370.2 11402.6 11385 11401.8 11382.5 11362.5 11353.6 11368.9 11365.3 11377.3 11375.3 11385.2 11364.7 11357 11366.8 11337.1 11348.1 11316.3 11308.3 11322.2 11311 11341.8 11350.1 11340.1 11348.3 11338.4 11379.9 11395.1 11368.1 11363.4 11342.3 11329.5 11317.9 11318.7 11304.5 11256.4 11277.6 11247.3 11264.2 11247.9 11245.6 11243.5 11257.1 11289.5 11250.5 11252.9 11243.2 11278.9 11323.5 11299.4 11328.1 11306.9 11311.5 11317.8 11308.3 11302.3 11276.2 11295.2 11252.7 11267.4 11268.3 11265.8 11271.8 11266.6 11280.2 11273.3 11300.6 11280.5 11298.7 11341.9 11336.2 11354.5 11351 11344.7 11346.5 11321.8 11358.6 11340.5 11352.6 11333.3 11347.1 11369.5 11352.9 11359.9 11335.2 11308.9 11331.4 11319.5 11344.5 11337.1 11352.8 11371.9 ...      
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    11356 11354.2 11335.5 11372.6 11370.7 11386.8 11363.4 11358.3 11397.9 11383.7 11396.8 11397.8 11385.2 11401.2 11395.9 11398.1 11394 11399.5 11373.6 11388.2 11377.5 11394.6 11414 11393.3 11406.4 11405.6 11410.5 11434.6 11413.3 11453.9 11439.2 11457.6 11458.4 11446.7 11439.1 11433.6 11441.8 11414.7 11436.4 11403.5 11450.9 11432.5 11439.6 11473.3 11449.6 11463.1 11452.3 11427.2 11401.4 11405.6 11360.7 11366.5 11336.1 11317.6 11289.2 11306.6 11306.7 11302.1 11350.6 11343.2 11368.7 11370 11365.4 11334.1 11317.6 11336 11305.5 11330.4 11306.5 11317.9 11321.9 11313.5 11344.5 11307.2 11335.5 11316.7 11334.7 11313.4 11326.3 11313.2 11307.2 11334.8 11321 11323.6 11317.9 11338.3 11330.7 11314.4 11334.7 11335.3 11353.3 11341.7 11366.5 11351.7 11353.6 11364.3 11361 11351.9 11337.9 11372.8];
Fx = fft(x - mean(x));
plot(abs(Fx(1:10)))

[Chunru]

Stop making nonsense please.

https://www.mathworks.com/matlabcentral/answers/876508-how-to-find-the-exact-value-of-the-frequency-by-matlab?s_tid=srchtitle

[Haya Ali]

I am so sorry that you are hurt and you talk to people like this. If you don't understand my question that doesn't mean that I am talking nonsense. Take care.

[Chunru]

You asked the question. People answered it in details. You asked again and said people don't understand your question. Please respect the people spending effort to help you.

Can I assume you are the same person posting the following question?

https://www.mathworks.com/matlabcentral/answers/876508-how-to-find-the-exact-value-of-the-frequency-by-matlab?s_tid=srchtitle

[Haya Ali]

Hi Chunru, Maybe i was unable to explain my question in a right way. Thank you for your help in the previous post. I was confused because i was getting the wrong answer suing that code but when I replaced

idx = idx + (10-1);

by

idx = idx + r(1) - 1; % as suggested by walter

the answer is right.

Thanks again.

Answer 1

[Steven Lord]

Index into the x vector using the output of islocalmax.

 x = 1:100;
 A = (1-cos(2*pi*0.01*x)).*sin(2*pi*0.15*x);
 tf = islocalmax(A);
 plot(x, A, 'k-+');
 hold on
 plot(x(tf), A(tf), 'go', 'MarkerSize', 8, 'MarkerFaceColor', 'g')

[Chunru]

The same question from the same OP has been answed in details:

the following question?

https://www.mathworks.com/matlabcentral/answers/876508-how-to-find-the-exact-value-of-the-frequency-by-matlab?s_tid=srchtitle