I use latex for taking class notes. But I find it hard to sketch function graphs within a short time period using tikz. Also, I am wondering, is there any IDE takes a "handwriting", converts it to image, and then insert as a figure?
There are some ways to do this, but neither of the ones I use solves your problem entirely:
- GeoGebra can plot functions quite conveniently and offers export into TikZ code.
- TikZEdit offers WYSIWIG to some extent, so you might give it a try.
- Inkscape can export to pdf, which will give you nice vector graphics. It also supports insertion of LaTeX text so the result looks consistent with the rest of the document (i.e. it creates an image and lets LaTeX render the texts on given positions over it).