How to convert strings to float in R?

[Jacob-Bishop]

Type.convert() seems to convert to numeric, but it doesn't have an argument to specify which kind of numeric value, and defaults to double.

[jmbejara]

To complete this exercise, I used a combination of the functions gsub and as.numeric.

[Jacob-Bishop]

The documentation I found (see below) seems to suggest as.numeric also produces doubles. Am I missing something?

https://www.rdocumentation.org/packages/base/versions/3.5.0/topics/numeric

[jmbejara]

I don't think that base R supports floats. The point of the assignment is to change from a string representation to a floating point number---whether that's a float or a double is unimportant. Plus, a Python float is not the same thing as a float vs double in a language like, say, C or C++.

[Jacob-Bishop]

Interesting, I didn't know that.

Does that hold for numpy/Pandas too, or does dtype=float give c types?

[jmbejara]

It's a little more complicated than that. For example, Numpy defines it's own data types. But Numpy is built in C. Python (the standard implementation) is also built in C. Some data types are platform dependent. (We once discussed in class how this might depend on whether your machine has a 32 or 64 bit architecture, etc.)

I'm don't really know the details. You might check these out:

• https://docs.scipy.org/doc/numpy-1.13.0/user/basics.types.html
• https://jakevdp.github.io/PythonDataScienceHandbook/02.01-understanding-data-types.html