I want to draw this plot. I know how to do it with data. But here I don't have any data. And I want to draw this. How would I do it?
As others have said, if you don't have the data values, you need to generate them using a function. The easiest way is to use PGFPlots and simply plot a function f(x) where x is sampled at regular intervals within some range. For example, to plot f(x)=x^3, you could use the following code:
For more complicated functions, and especially when your x samples aren't regularly spaced, you can either calculate the data outside of TeX and simply include it in your document, or you could use PGFPlotstable to generate a data table inside the document.
Here's an example where I created a table with three columns: x, an intermediate step, and y, based on the code found in the metadata included with the Wikipedia image you used: