I have a set of data as such: I need to iterate over each value in the first column, find the corresponding maximum value in the second column and then store in a new array (or delete the other values from this array). For this example the final output would therefore be: I have managed to write a piece of
Tag: numpy
Different output while using fit_transform vs fit and transform from sklearn
The following code snippet illustrates the issue: Can someone explain as to why the first output is not zero and the second output is? Answer Using this works: Apparently svd_solver = ‘random’ (which is what ‘auto’ defaults to) has enough process difference between .fit(X).transform(X)…
Rearrange elements in numpy array to plot a 3d array in 2d, preserving grouping
Hello I have a 3d numpy array of shape (nc, nx, ny). I would like to plot it (with matpoltlib) using x and y as the axis, but in such a way that all c values are close to each other and arranged in a rectangle around a central value (you can assume nc is a power of 2). Thanks
How to multiply all numerical columns of a dataframe by a one-dimensional array?
I have a dataframe df of shape r x c, with 1 text column (with non-unique values) and the other columns all floats. I then have an array mult of size r. I would like each numerical column of the dataframe to be multiplied by the corresponding item of the array. Ie the desired output is that value_1[0] should …
How to plot a trend line in a scatter plot from multiple dataframe data?
I have 4 data frames, which are df, df1, df2 and df3.I have plotted these data into a scatter plot. To plot trend line, I use the below code found in stackoverflow. However, this only gives the trendline from df1. I would like to plot a trendline which includes the data from df1, df2 and df3. Answer It uses d…
Damping harmonic oscillation code with python
I don’t know that how make the code the three graph in damping harmonic oscillation model, [X – t(time)], [V(velocity) – t(time)], [a(acceleration) – t(time)] graph i can make the [X – t(time)] graph but i don`t know how to make another graphs.. Answer Why can’t you just ta…
Fastest method of bilinear weighting of a 2D point cloud onto a grid
Given a point (0.8, 0.6) and an intensity (3), one can bi-linearly “reverse interpolate” a single point onto a 2×2 grid with integer indices (0,0) -> (1,1). The points and grid are oriented with the first entry increasing downwards, and the second entry increasing towards the right. On suc…
Adding new points to point cloud in real time – Open3D
I am using Open3D to visualize point clouds in Python. Essentially, what I want to do is add another point to the point cloud programmatically and then render it in real time. This is what I have so far. I could not find any solution to this. In the code below, I show one possible solution, but it is not
Too many indices for array | python
I’m trying to copy arrays to a pandas Dataframe and get the error “too many indices for array”. The error occurs in these lines: pr_daily and rad_daily are numpy arrays of of the same length. Traceback (most recent call last): File “C:Users…Downloadspython_scriptspv.py”, li…
“NameError: name ‘numpy’ is not defined” when calling eval()
The line for e2 (but not e1) generates an error: Why? Answer I solved it by replacing: with: