Make an average curve graph

i wrote two code one is 20 line trend another i want to creat an average curve graph ， but there is a little strange, It feels like the average will be between 4-6

code1----------------------------

img1 = imread('20230814.jpg');

img = (-0.2./ (-0.3 ./ (46 ./ double(img1) - 1)) + 1) * 5;

center_row_data = img(415:435, 1:755);

subplot(2,1,2)

plot(center_row_data.');

title('Plotting each Row as a Line');

code2---------------------------

img1 = imread('20230814.jpg');

img = (-0.2./ (-0.3 ./ (45.39 ./ double(img1) - 1)) + 1) * 5.3;

center_row_data = img(415:435, 1:755);

average_data = mean(center_row_data, 2);

subplot(2, 1, 2);

plot(average_data);

title('average trend');

xlabel('列');

ylabel('温度');

[Dyuman Joshi]

"but there is a little strange, It feels like the average will be between 4-6"

The average values are, in fact, in between 4 and 6, as can be seen from the plot.

[bozheng]

well i mean is picture two didn't show it it show 4.3 to 4.6

[Dyuman Joshi]

Unless mentioned specifically, MATLAB selects the limits on the axes based on the range of your data.

You can change the limits shown on the y-axis via ylim.

[Dyuman Joshi]

Any updates, @bozheng?