Sorry, you do not have a permission to ask a question, You must login to ask question.

• 8

## PCA on sklearn – how to interpret pca.components_

• 8

I ran PCA on a data frame with 10 features using this simple code: pca = PCA() fit = pca.fit(dfPca) The result of pca.explained_variance_ratio_ shows: array([ 5.01173322e-01, 2.98421951e-01, 1.00968655e-01, ...

• 1

## Python atan or atan2, what should I use?

• 1

My formula f=arctan(ImZ/ReZ) There are two options: Option 1 (atan): ImZ=-4.593172163003 ImR=-4.297336384845 >>> z=y/x >>> f1=math.atan(z) >>> f1 0.8186613519278327 Option 2 (atan2) >>> f=math.atan2(y,x) >>> f -2.3229313016619604 Why are these two results different?

• 1

## Discarding alpha channel from images stored as Numpy arrays

• 1

I load images with numpy/scikit. I know that all images are 200×200 pixels. When the images are loaded, I notice some have an alpha channel, and therefore have shape (200, 200, 4) instead of (200, 200, 3) which I ...

• 3

## Python : easy way to do geometric mean in python?

• 3

I wonder is there any easy way to do geometric mean using python but without using python package. If there is not, is there any simple package to do geometric mean?

• 8

## How can I solve system of linear equations in SymPy?

• 8

Sorry, I am pretty new to sympy and python in general. I want to solve the following underdetermined linear system of equations: x + y + z = 1 x + y + 2z = 3

• 9

## How do I do exponentiation in python?

• 9

def cube(number): return number^3 print cube(2) I would would expect cube(2) = 8, but instead I’m getting cube(2) = 1 What am I doing wrong?

• 3

## How to check change between two values (in percent)?

• 3

I have two values (previous and current) and I want to check change between them (in percent): (current/previous)*100 But if the previous value is 0 I get Division By Zero, and if value will not change I get 100%.

• 4

## How to interpolate a line between two other lines in python

• 4

Note: I asked this question before but it was closed as a duplicate, however, I, along with several others believe it was unduely closed, I explain why in an edit in my original post. So I would ...

• 9

## How to know the angle between two points?

• 9

I am making small game with pygame and I have made a gun that rotates around its center. My problem is that I want the gun to rotate by itself to the enemy direction, but I couldn’t do ...

• 1

## Calculate angle (clockwise) between two points

• 1

I have been not using math for a long time and this should be a simple problem to solve. Suppose I have two points A: (1, 0) and B: (1, -1). I want to use a program (Python or whatever ...