Relief of Complex Gamma Fcn — was this hand drawn?

This pic is from an older text called Tables of Higher Functions (interestingly both in German first then English second) that I jumped at buying from some niche bookstore for $40. Was this hand drawn? I think I’ve seen was it that mathegraphix or something like that linked by @fresh_42 somewhere on PF that had an example plot similar to these.

I guess it depends on when the book was published, but my guess is it was hand drawn by an artist versed in math or at the direction of a mathematician. Or a draftsman drew it getting the perspective accurate.

As an example of the quality of hand-drawn charts here's Charles Minard's famous Napoleon chart:

https://datavizblog.files.wordpress.com/2013/05/map-full-size1.png

But I could be wrong about it too.

Yes, it looks like this was hand drawn. Mathegraphix is a software program that allows for the creation of mathematical plots, so it's possible that the author used that program to create the plots in this text. The style does look similar to what I've seen from Mathegraphix.