# Questions tagged [vector]

12250 questions

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### Access element of a vector in a Spark DataFrame [closed]

I want to access the vector elements in the spark dataframe shown below:-
name_cv
(262144,[88783,143375,220659,228248],[1.0,1.0,1.0,1.0])
(262144,[220659],[1.0])
(262144,[75742],[1.0])
(262144,[68369,95745,107911,224494],[1.0,1.0,1.0,1.0])
& so on
I want to to access 88783,143375,220659,228248 and a...

1

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1

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116

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### Scala - Update mutable maps inside immutable Vector

I'm trying to build a Vector[Map[String, Any]] in Scala. I know that Vector is immutable, and I'm using mutable Map.
When I try to do this:
def calculate_objectives(pop: Vector[Map[String, Any]]): Unit ={
for (i decode(pop(i)('genome').asInstanceOf[Vector[Int]]))
pop(i) = pop(i) + ('objective' -> V...

1

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0

answer

88

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### 'x' must be atomic for 'sort.list', using dbFD(). FD package

I am trying to run
dbFD(traits, as.matrix(abun))
but i receive this error:
Error in sort.list(y) : 'x' must be atomic for 'sort.list'
Have you called 'sort' on a list?
my data looks similar, but larger to this:
t1 t2 t3 ... sp1 sp2 sp3 sp4....
sp1 0.2 10...

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2

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38

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### Can we use vector in c++ to take user input of unknown size only till we hit enter?

I was trying to take user input in a vector in c++, as vector is a dynamic data structure i wanted it to take input as long as user wants and when the user hit enter key it should stop taking the input (just as a string) only difference i want to do it in an integer vector, but i am unable to do so...

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1

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16

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### Error in multiplying matrix vector - invalid operands to binary * (have 'double *' and 'double *')

I'm trying to multiply a large and random matrix (NxN) and a random vector (N), using pointers.
Why am i getting an error type 'invalid operands to binary * (have 'double *' and 'double *')' ?
The error seems to be in ptr3[i][j] = ptr3[i] + ptr1[i] * ptr2[k];
but I can't figure out why this doesn...

1

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1

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22

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### Vector definition with varying length

I'm trying to figure out how to write a vector command allowing for variable length.
Suppose that I have variables Item1 to Item7. I can write a vector statement...
VECTOR Item = Item1 to Item7.
In another situation I have 20 items instead of 7 (i.e., Item1 to Item20), and suppose I have a variable...

1

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0

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218

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### Using C# System..Numerics.Vector<T> to unpack / pack bits

I’m testing the capabilities of the .Net C# System.Numerics.Vector class for packing and unpacking bits.
I was hoping for Vector bitwise shift left/right functionality but that is not currently available so I tried to simulate shifting using arithmetic & logical methods as below. Here’s what I s...

1

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1

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50

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### Raytracer reflections inconsistent

I'm writing a simple raytracer in Python, however I'm having trouble adding reflections to spheres. My code works fine for planes leading me to believe I'm calculating sphere normals incorrectly. I also noticed that reflections are not the same when viewed from different angles so I added a video ou...

1

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1

answer

139

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### std::vector using back(), pop_back(), push_back(), get 'double free or corruption' error

I have the following code:
struct branchInfo{
Quaternion r;
Vector3 p;
std::vector branchPoints;
};
std::vector LSystem::Turtle(){
std::vector b;
// The axiom should always start with a '[' at the start and a ']' at the end
for(unsigned int i = 0; i < axiom.length(); i++) {
char c = axiom[i];
if (c...

1

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1

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75

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### Project vector w onto vector v and draw perpendicular line - preparation for PCA

I want to do vector projection as preparation for PCA where I followed This tutorial for the calculation of the vector projection.
w is the vector which 'points' onto the data points, v is the vector which spans the line onto which w should be projected.
The code is:
import numpy as np
import matp...

1

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2

answer

103

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### Using 'new' in a template class is type safe?

I'm working on my own vector implementation, and one of the guys said on IRC, using 'new' to allocate memory in a template class isn't type safe. For example in this code:
// resize array when needed
template
void myVector::resize()
{
vCapacity += 5;
T* temp = new T[vCapacity]();
for (unsigned i =...

1

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0

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52

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### Array of vector

I am using an array of vectors. I have to count number of rows in the array. I am using the technique used for a 2D array. But it does not give desired output.
int main()
{
int i,p=7;
vector *mat=new vector[p];
int k=5;
for(i=0;i

1

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1

answer

44

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### How can I use iterator to pass the value in a recursive function in c++?

If I run the code as below then it crashes for the inputs. But if I do not use the iterator and use the code written in the comment section(in DFS() function) then it gets run well and doesn't crash anymore. I can't understand why this code is getting crashes by iterator.
#include
#include
#include...

1

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0

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35

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### Print value from data frame, not rownumber

I have a simple data frame without row names (so row number is created automatically) and just one named Column ('sec'). And I want to get the value inside the cell 1:1.
The attributes are the following:
$`names`
[1] 'sec'
$row.names
[1] 1
$class
[1] 'data.frame'
When I run: secCluster[1,1] I'am ge...

1

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1

answer

253

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### Quickest way to mask raster using polygons from gml file

I am building a headless script to preprocess Sentinel images. For info the session is setup as follows:
import sys
import os
import qgis
from qgis.core import *
#from PyQt4.QtGui import *
QgsApplication.setPrefixPath('/usr', False)
app = QgsApplication([], False)
app.initQgis()
sys.path.append('/us...

1

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2

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65

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### Data vectorization (get_dummies 3 columns to matrix)

I have a task, which must be optimally solved. I have 50 categories and 10,000 stores that can have products from these categories, but all this in 3 columns
id_store category qnty
1 1 50
1 2 32
1 15 44
2 1 333
2 4 33
2...

1

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1

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38

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### Figure created from contour changes to be in raster format when the number of rows and columns larger than some threshold

A 2D data matrix (data, 100 rows by 100 cols) was plotted using 'contour' function in matlab, and the figure was saved as *.emf file. Expectedly when I insert the emf figure into MS word file, the figure is a vector graphic. But when I improve the resolution of the data, i.e. using imresize in matla...

2

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1

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21

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### output a collection of collections using templated operator<<

I want to output a collection of collection (a vector of vectors in this case) by calling the outside collection once by operator

1

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0

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47

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### R Atomic Vectors, how do access elements

I probably have a basic question, but this is the first time I've really gotten to grips with atomic vectors. I loaded data from a state file and placed into a data frame. Looks something like this:
$ hv202 : atomic 13 13 43 13 13 13 13 13 42 21 ...
..- attr(*, 'label')= chr 'source of non-drinki...

1

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0

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33

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1

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0

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13

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### Synchronizing ASC File Reading with Video Frames without having any common value

I have Vector ASC Log files and it's respective video files which are logged for same duration (lets say 5 minutes). Following is the Vector ASC File Format :
.
.
.
Video is getting logged in .avi format. While replaying I am loading both ASC file and it's respective video file.
Problem is, how can...

1

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1

answer

29

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### Creating a dataframe with vector entries

I am trying to create a pandas dataframe where the entry in a single cell is a numpy array. For example, given a list of chemical compounds - A2B3C4, D1A2J3 etc, I create a numpy array for each of them so that:
firstium - A2B3C4 - [2,3,4,0,0,0,0.....]
secondium - D1A2J3 - [2,0,0,1,......3....]
I wou...

1

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1

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65

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### Android drawable shape in xml

How I can create single vector xml drawable like this (black shape):
To be able to use this in imageView and change it color

1

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0

answer

52

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### R vector in network analysis

I am working on Network analysis in R. I am getting an error that says argument 2 is not a vector.
Here is I have up until the error (the error is on the links = links line):
library(igraph)
nodes = read.csv('vertex.csv', header=T, as.is=T)
links = read.csv('edges.csv', header=T, as.is=T)
head(node...

1

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1

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379

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### Removing a pair from a vector of pairs [duplicate]

This question already has an answer here:
How do I erase an element from std::vector by index?
10 answers
I have a vector of pairs
std::vector lambda;
I would like to remove the kth element, i.e
lambda.erase(&lambda[k]);
lambda.erase(lambda[k]);
Both of these attempts throws a no matching function...

1

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0

answer

25

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### About cgdsr R package

I installed cgdsr R package and I wanted to use a below function ranging from 0 to the end, which means I want to see all genes.
But I don't know how to set c(1:?) that is a vector of gene names or a String specifying a single gene (required) for all genes.
getProfileData(mycgds,c(1:100),mygeneticpr...

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27

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3

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0

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39

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### operator< gives operator __surrogate_func error

I've implemented operator< for my c++ classes and when I tried it for a class that contains object vector; it fails and gives operator __surrogate_func
When I remove object vector from class, everything is OK.
I found this similar question about question but I dont know why Im getting this error? Be...

1

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0

answer

61

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### Multiplication of RDD row to all other rows in PySpark

I have an RDD of DenseVector objects and I want to:
Select one of these vectors (one row)
Perform a multiplication of this vector to all other vector rows in order to compute a similarity (cosine)
Basically I am trying to perform a dot product between a vector and a matrix, starting from an RDD. For...

1

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1

answer

95

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### How do I group consecutive dates within a Vector in R?

I have a vector of dates below;
dates

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0

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70

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### RAM consumption too high for vector allocation under R

I have difficulty under R with a problem, apparently quite common 'cannot allocate vector size XXX GB'.
In my case there are two procedures, one with a failure on a vector of 1.1 GB and the other on a vector of 4.8 GB
I work on following hardware resources : Windows 10 PC with an 8-core processor (X...

1

votes

1

answer

94

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### Converting float vector to double

Im rather new to c++ so forgive my ignorance on this.
Im trying to convert a double vector to a float vector for uses in certain cases( im aware there is a precision loss).
The structure of the vectors is simply,
struct Dvector
{
public:
double X;
double Y;
double Z;
Is there a simple function to cr...

1

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1

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869

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### React Native Custom Icons w/ Vector Icons

I'm new to React Native and I'm trying to have icons that are able to have their color changed based on json data received. I've been able to use React Native Vector Icons. However, I have my own icons that I would like to use. On the linked repo page there is something that talks about generating y...

1

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0

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13

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### create a lineal-log-log-lineal partition of interval [a,b] in matlab, but matching steps

i want to create a vector x from a to b, in the following way.
I have an interest point c , a

1

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0

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18

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### Make only specific path stretchable for vectors

This is the original vector:
This what normally happen if you stretch a vector along x-axis:
This is what I want to achieve:
I know that I can achieve this by making custom view class or creating separate views. But I want to know if there is any way to achieve this using only resource file somethin...

1

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1

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46

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### C++ Vector understanding

I am currently using codewars.com to practice my coding skills. I finished one of the problems and wanted to check what other people's solutions were and I found one I couldn't understand. It's much better than my solution and I would like to understand it more. such what does '*std' do exactly. wha...

1

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1

answer

52

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### C++: Queue of custom data type vector error

I am using a thread-safe queue of custom type vector. it shows the following error. I am not sure what I am missing here.
Error C2664 'std::vector>::vector(std::vector &&,const _Alloc &) noexcept()': cannot convert argument 2 from 'int' to 'const std::allocator &'.
#include
#include
#include
#...

1

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1

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302

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### Icons not loading correctly react-native-vector-icons

I am using React-Native to build an application. I went on FlatIcon to get some custom icons, which I uploaded to IcoMoon and followed the installation steps to properly implement them on react-native.
The problem is the result I am getting is completely different to what I installed.
This the Icon...

1

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0

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38

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### Vector of vector re-size

So I have two vector of vectors like:
matchings_vec = Vector{Vector{Vector{Vector{Any}}}}(num_tilt1)
Minfoall_vec = Vector{Vector{Vector{Vector{Vector{Vector{Float64}}}}}}(num_tilt1)
I defined it as:
matchings_vec = [Vector{Any}() for i in 1:num_tilt1]
Minfoall_vec = [Vector{Float64}() for i in 1:nu...

1

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0

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39

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### How to create rounded corner rectangle shape using gradient and vector

Hello everyone I have to create background rounded corner rectangle of layout just like shown in attached image. I mentioned it in image by black box and arrow in image.
Please suggest me what I can use for it gradient or vector and how can we create.