Cumulative Density Function. Digital Image Processing

as you can see in the table, I have to write it as a code in matlab but I have problem in finding cdf, where cdf1 = pdf1, cdf2 = pdf1 + pdf2,

cdf3 = cdf2 + pdf3 = pdf1 + pdf2 + pdf3 etc... But Iam facing a problem in writing the code. Any help please.

Answer 1

[yanqi liu]

sir，is it use in histeq？may be check as follow

[mohammad mehio]

no, not like this