As part of my nightwatchjs testing script, I have a 'dynamic' array that I would like to add a character to.
So, at the moment my array has a value of 4000, but I would like this to read 4,000.
This means that I need to add a , to my array.
The issue I have however, is that this value could change the next time I run the test script, so it could be 10000 or 100000.
So I suppose what I'm asking is whether it's possible to "select a value 3 elements from the end of my array?"
So no matter what or how many elements are in the array, the array will read xx,000.
Any help would be much appreciated. Many thanks.
Does this array have a single value? If so, why is it an array instead of just a variable?
You can use toLocaleString() to add commas to a numeric value, but it will return a string and not a number.
let arr = [4000]
let num = arr[0]
let commas = num.toLocaleString()
console.log(commas)
// "4,000"
Related
Hi i am struggling to get my array in Pinescript to produce anything other than a list of Nan. I am trying to create an array of the % difference of the low and 20sma when price bounces off the 20sma but currently when i print the array it only has Nan values.
sma_20 = sma(close,20)
sma_20_touch_band = open>sma_20 and low<=sma_20
sma_20_dif = ((low-sma_20)/sma_20)
sma_20_array = array.new_float(100)
if sma_20_touch_band
array.push(sma_20_array, sma_20_dif)
array.shift(sma_20_array)
That is most likely caused by not using a var array. Without the var keyword, your array will be re-initialized on each bar. You need to initialze your array once, and manipulate its elements later on. Therefore make it:
var sma_20_array = array.new_float(100)
Also, I'm not so sure about your usage of the array.shift() function.
You push something to the array, but with the array.shift() you remove the first element from the array. At the end of the day, you remove what you have just added. At least this is what I think is happening.
Basically, I’m given a list of strings such as:
["structA.structB.myArr[6].myVar",
"structB.myArr1[4].myArr2[2].myVar",
"structC.myArr1[3][4].myVar",
"structA.myArr1[4]",
"structA.myVar"]
These strings are describing variables/arrays from multiple structs. The integers in the arrays describe the size each array. Given a string has a/multiple arrays (1d or 2d), I want to generate a list of strings which go through each index combination in the array for that string. I thought of using for loops but issue is I don’t know how many arrays are in a given string before running the script. So I couldn’t do something like
for i in range (0, idx1):
for j in range (0, idx2):
for k in range (0, idx3):
arr.append(“structA.myArr1[%i][%i].myArr[%i]” %(idx1,idx2,idx3))
but the issue is that I don’t know how I can create multiple/dynamic for loops based on how many indexes and how I could create a dynamic append statement that changes per each string from the original list since each string will have a different number of indexes and the arrays will be in different locations of the string.
I was able to write a regex to find all the index for each string in my list of strings:
indexArr = re.findall('\[(.*?)\]', myString)
//after looping, indexArr = [['6'],['4','2'],['3','4'],['4']]
however I'm really stuck on how to achieve the "dynamic for loops" or use recursion for this. I want to get my ending list of strings to look like:
[
["structA.structB.myArr[0].myVar",
"structA.structB.myArr[1].myVar",
...
"structA.structB.myArr[5].myVar”],
[“structB.myArr1[0].myArr2[0].myVar",
"structB.myArr1[0].myArr2[1].myVar",
"structB.myArr1[1].myArr2[0].myVar",
…
"structB.myArr1[3].myArr2[1].myVar”],
[“structC.myArr1[0][0].myVar",
"structC.myArr1[0][1].myVar",
…
"structC.myArr1[2][3].myVar”],
[“structA.myArr1[0]”,
…
"structA.myArr1[3]”],
[“structA.myVar”] //this will only contain 1 string since there were no arrays
]
I am really stuck on this, any help is appreciated. Thank you so much.
The key is to use itertools.product to generate all possible combinations of a set of ranges and substitute them as array indices of an appropriately constructed string template.
import itertools
import re
def expand(code):
p = re.compile('\[(.*?)\]')
ranges = [range(int(s)) for s in p.findall(code)]
template = p.sub("[{}]", code)
result = [template.format(*s) for s in itertools.product(*ranges)]
return result
The result of expand("structA.structB.myArr[6].myVar") is
['structA.structB.myArr[0].myVar',
'structA.structB.myArr[1].myVar',
'structA.structB.myArr[2].myVar',
'structA.structB.myArr[3].myVar',
'structA.structB.myArr[4].myVar',
'structA.structB.myArr[5].myVar']
and expand("structB.myArr1[4].myArr2[2].myVar") is
['structB.myArr1[0].myArr2[0].myVar',
'structB.myArr1[0].myArr2[1].myVar',
'structB.myArr1[1].myArr2[0].myVar',
'structB.myArr1[1].myArr2[1].myVar',
'structB.myArr1[2].myArr2[0].myVar',
'structB.myArr1[2].myArr2[1].myVar',
'structB.myArr1[3].myArr2[0].myVar',
'structB.myArr1[3].myArr2[1].myVar']
and the corner case expand("structA.myVar") naturally works to produce
['structA.myVar']
In shell script (!/bin/sh) I have array elements:
u[1]="someString"
u[2]="anotherString"
u[3]="aThirdString"
u[4]="aFourhString"
I want to build a new string, which will display the string values of u array elements that I want and separated by semi-column (;). I want to do the following:
totalString=""
for k in {2..4}; do
totalString+="${u[k]};"
done
But I cannot make it to work. First of all, for some reason k is interpreted like a {2..4} at the above, instead of evaluating the value of u[k] every time to finally display the desired:
anotherString;aThirdString;aFourhString
Note that the example array elements are not always the same as above example. I could have more than 4, or less. I am counting and define them with other part of code and I want to display some of them only at the total new string.
I am trying to create a string array which will be fed with string values read from a text file this way:
labels = textread(file_name, '%s');
Basically, for each string in each line of the text file file_name I want to put this string in 10 positions of a final string array, which will be later saved in another text file.
What I do in my code is, for each string in file_name I put this string in 10 positions of a temporary cell array and then concatenate this array with a final array this way:
final_vector='';
for i=1:size(labels)
temp_vector=cell(1,10);
temp_vector{1:10}=labels{i};
final_vector=horzcat(final_vector,temp_vector);
end
But when I run the code the following error appears:
The right hand side of this assignment has too few values to satisfy the left hand side.
Error in my_example_code (line 16)
temp_vector{1:10}=labels{i};
I am too rookie in cell strings in matlab and I don't really know what is happening. Do you know what is happening or even have a better solution to my problem?
Use deal and put the left hand side in square brackets:
labels{1} = 'Hello World!'
temp_vector = cell(10,1)
[temp_vector{1:10}] = deal(labels{1});
This works because deal can distribute one value to multiple outputs [a,b,c,...]. temp_vector{1:10} alone creates a comma-separated list and putting them into [] creates the output array [temp_vector{1}, temp_vector{2}, ...] which can then be populated by deal.
It is happening because you want to distribute one value to 10 cells - but Matlab is expecting that you like to assign 10 values to 10 cells. So an alternative approach, maybe more logic, but slower, would be:
n = 10;
temp_vector(1:n) = repmat(labels(1),n,1);
I also found another solution
final_vector='';
for i=1:size(labels)
temp_vector=cell(1,10);
temp_vector(:,1:10)=cellstr(labels{i});
final_vector=horzcat(final_vector,temp_vector);
end
I am currently trying to figure out how to design some sort of loop to insert data into an array sequentially. I'm using Javascript in the Unity3D engine.
Basically, I want to store a bunch of coordinate locations in an array. Whenever the user clicks the screen, my script will grab the coordinate location. The problem is, I'm unsure about how to insert this into an array.
How would I check the array's index to make sure if array[0] is taken, then use array[1]? Maybe some sort of For loop or counter?
Thanks
To just add onto the end of an array, just use .push().
var myArray = [];
var coord1 = [12,59];
var coord2 = [87,23];
myArray.push(coord1);
myArray.push(coord2);
myArray, now contains two items (each which is an array of two coordinates).
Now, you wouldn't do it this way if you were just statically declaring everything as I've done here (you could just statically declare the whole array), but I just whipped up this sample to show you how push works to add an item onto the end of an array.
See https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/push for some reference doc on push.
In case you need to know the array's length when reading the array in the future, you can use the .length attribute.
var lengthOfArray = myArray.length;
Using the .push() method as suggested by jfriend00 is my recommendation too, but to answer your question about how to work out what the next index is you can use the array's length property. Because JavaScript arrays are zero-based The length property will return an integer one higher than the current highest index, so length will also be the index value to use if you want to add another item at the end:
anArray[anArray.length] = someValue; // add to end of array
To get the last element in the array you of course say anArray[anArray.length-1].
Note that for most purposes length will give the number of elements in the array, but I said "one higher than the current highest index" above because JavaScript arrays are quite happy for you to skip indexes:
var myArray = [];
myArray[0] = "something";
myArray[1] = "something else";
myArray[50] = "something else again";
alert(myArray.length); // gives '51'
// accessing any unused indexes will return undefined