  C RUBY-ON-RAILS MYSQL ASP.NET DEVELOPMENT RUBY .NET LINUX SQL-SERVER REGEX WINDOWS ALGORITHM ECLIPSE VISUAL-STUDIO STRING SVN PERFORMANCE APACHE-FLEX UNIT-TESTING SECURITY LINQ UNIX MATH EMAIL OOP LANGUAGE-AGNOSTIC VB6 MSBUILD # How to add a vector to a matrix  » python » How to add a vector to a matrix

By : Napior
Date : October 16 2020, 06:10 PM
I wish did fix the issue. I have a matrix of shape (13,10) I want to add vector of zeros till the shape becomes 20 rows and 10 columns code :
``````z = np.zeros((13, 10))
x = np.zeros((1, 10))
y = np.vstack((z, x))
y.shape
(14, 10)
`````` ## Vector-matrix & matrix-matrix multiplication using SSE for any size of input matrix and vector

By : MichaelDroid
Date : March 29 2020, 07:55 AM
Since your containers (matrixes and vectors) do not have necessarily a size which is a multiple of 4 floats (16 bytes) this is incorrect. ## can we change the vector into matrix in numpy with the elements in the vector repeats in a matrix with m*n dimensions

Date : March 29 2020, 07:55 AM
help you fix your problem If I understand the question correctly you could simply use np.repeat and reshape:
code :
``````>>> import numpy as np

>>> arr = np.array([1,2,3,4])
>>> n = 3
>>> np.repeat(arr, n).reshape(-1, arr.size)
array([[1, 1, 1],
[2, 2, 2],
[3, 3, 3],
[4, 4, 4]])
``````
``````>>> n = 7
array([[1, 1, 1, 1, 1, 1, 1],
[2, 2, 2, 2, 2, 2, 2],
[3, 3, 3, 3, 3, 3, 3],
[4, 4, 4, 4, 4, 4, 4]])
`````` ## Error: requires numeric/complex matrix/vector arguments when using matrix times vector multiplication

By : Greg Gould
Date : March 29 2020, 07:55 AM
I hope this helps . This works fine. You must have some NAs in your cpi_calc table. Try na.omit(cpi_calc)
code :
``````cpi_calc <- read.table(text="0.358  0.359   0.06    0.419   0.191   0.296
100 100 100 100 100 100
99.99   100 100.07  100.01  100.8   101.59
99.52   99.58   99.94   100.01  101.03  101.38
99.46   99.44   99.85   100.01  101.03  101.03
99.13   99.37   99.79   99.97   101 101.82",header=FALSE)

as.matrix(cpi_calc[2:6, 1:6]) %*% t(cpi_calc[1, 1:6])
1
2 168.3000
3 168.9282
4 168.5832
5 168.4024
6 168.4669
`````` ## How do I multiply a matrix by a vector in python without any built in functions where both the vector and matrix are inp

By : user2580804
Date : March 29 2020, 07:55 AM
this one helps. Input validation
First, you should introduce some validation checks on the input.
code :
``````ncols = len(matrix1)
for row in matrix1[1:]:
if len(row) != ncols:
#stop the program and raise an error to the user.
`````` ## Non-intuitive perf diff between `matrix * vector`, `matrix’ * vector` and `copy(matrix’) * vector` Usage Performance bla

By : user3232940
Date : March 29 2020, 07:55 AM 