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.
I'm uploading a spreadsheet and mapping the spreadsheet column headings to those in my database. The email column is the only one that is required. In StringB below, the ,,, simply indicates that a column was skipped/ignored.
The meat of my question is this:
I have a string of text (StringA) comes from a spreadsheet that I need to find in another string of text (StringB) which matches my database (this is not the real values, just made it simple to illustrate my problem so hopefully this is clear).
StringA: YR,MNTH,ANNIVERSARIES,FIRSTNAME,LASTNAME,EMAIL,NOTES
StringB: ,YEAR,,MONTH,LastName,Email,Comments <-- this list is dynamic
MNTH and MONTH are intentionally different;
excelColumnList = 'YR,MNTH,ANNIV,FIRST NAME,LAST NAME,EMAIL,NOTES';
mappedColumnList= ',YEAR,,MONTH,,First Name,Last Name,Email,COMMENTS';
mappedColumn= 'Last Name';
local.index = ListFindNoCase(mappedColumnList, mappedColumn,',', true);
local.returnValue = "";
if ( local.index > 0 )
local.returnValue = ListGetAt(excelColumnList, local.index);
writedump(local.returnValue); // dumps "EMAIL" which is wrong
The problem I'm having is the index returned when StringB starts with a , returns the wrong index value which affects the mapping later. If StringB starts with a word, the process works perfectly. Is there a better way to to get the index when StringB starts with a ,?
I also tried using listtoarray and then arraytolist to clean it up but the index is still off and I cannot reliably just add +1 to the index to identify the correct item in the list.
On the other hand, I was considering this mappedColumnList = right(mappedColumnList,len(mappedColumnList)-1) to remove the leading , which still throws my index values off BUT I could account for that by adding 1 to the index and this appears to be reliably at first glance. Just concerned this is a sort of hack.
Any advice?
https://cfdocs.org/listfindnocase
Here is a cfgist: https://trycf.com/gist/4b087b40ae4cb4499c2b0ddf0727541b/lucee5?theme=monokai
UPDATED
I accepted the answer using EDIT #1. I also added a comment here: Finding specific instance in a list when the list starts with a comma
Identify and strip the "," off the list if it is the first character.
EDIT: Changed to a while loop to identify multiple leading ","s.
Try:
while(left(mappedColumnList,1) == ",") {
mappedColumnList = right( mappedColumnList,(len(mappedColumnList)-1) ) ;
}
https://trycf.com/gist/64287c72d5f54e1da294cc2c10b5ad86/acf2016?theme=monokai
EDIT 2: Or even better, if you don't mind dropping back into Java (and a little Regex), you can skip the loop completely. Super efficient.
mappedColumnList = mappedColumnList.replaceall("^(,*)","") ;
And then drop the while loop completely.
https://trycf.com/gist/346a005cdb72b844a83ca21eacb85035/acf2016?theme=monokai
<cfscript>
excelColumnList = 'YR,MNTH,ANNIV,FIRST NAME,LAST NAME,EMAIL,NOTES';
mappedColumnList= ',,,YEAR,MONTH,,First Name,Last Name,Email,COMMENTS';
mappedColumn= 'Last Name';
mappedColumnList = mappedColumnList.replaceall("^(,*)","") ;
local.index = ListFindNoCase(mappedColumnList, mappedColumn,',', true);
local.returnValue = ListGetAt(excelColumnList,local.index,",",true) ;
writeDump(local.returnValue);
</cfscript>
Explanation of the Regex ^(,*):
^ = Start at the beginning of the string.
() = Capture this group of characters
,* = A literal comma and all consecutive repeats.
So ^(,*) says, start at the beginning of the string and capture all consecutive commas until reaching the next non-matched character. Then the replaceall() just replaces that set of matched characters with an empty string.
EDIT 3: I fixed a typo in my original answer. I was only using one list.
writeOutput(arraytoList(listtoArray(mappedColumnList))) will get rid of your leading commas, but this is because it will drop empty elements before it becomes an array. This throws your indexing off because you have one empty element in your original mappedColumnList string. The later string functions will both read and index that empty element. So, to keep your indexes working like you see to, you'll either need to make sure that your Excel and db columns are always in the same order or you'll have to create some sort of mapping for each of the column names and then perform the ListGetAt() on the string you need to use.
By default many CF list functions ignore empty elements. A flag was added to these function so that you could disable this behavior. If you have string ,,1,2,3 by default listToArray would consider that 3 elements but listToArray(listVar, ",", true) will return 5 with first two as empty strings. ListGetAt has the same "includeEmptyValues" flag so your code should work consistently when that is set to true.
I'm trying to have a cell array of cell array in order to store data in a structure.
Here is my example :
close all;
clear all;
clc;
register = struct('thing', [], ...
'positions', cell(1));
register.positions{1}{end+1} = {[45 36]};
register.positions{2}{end+1} = {[12 87]};
register
I got this following error message :
Cell contents reference from a non-cell array object.
Error in test (line 8) register.positions{1}{end+1} = {[45 36]};
I am definitely doing something wrong, but I have unsuccessfully tried many other things.
Thank you for your help
The cell has to be initialized first. Let's break it up: Your code
register = struct('thing', [], 'positions', cell(1));
actually creates a structure with two empty fields:
>> register
register =
thing: []
positions: []
Assigning directly using end (e.g. with register.positions{1}{end+1}=4) will fail, because end in the second level will try to determine the size of the cell at register.positions{1}, but register.positions itself is empty!
So, what do we do? We could ensure that at the first time a new element at the top level is referred to, we initialize it without referring to its content. For example, register.positions{1} = [] will do the job, and
register.positions{1}{end+1} = [45 36];
will then work. (Note: here I have not encapsulated the array in another set of curly braces, because from your comments above it seems they're not necessary.)
Now, to make this a bit more convenient, you preallocate the positions field with the number of elements ('cars' in your comment), if it is known (or a number larger than expected):
register = struct('thing', [], 'positions', {cell(1, 42)})
I want to make a condition that check if the cell array is empty then move to the next.
I got this index exceed matrix dimensions
Looking forward to hear from you
You can use isempty to check if an element is empty or not:
C = cell(5,1);
C{2} = 2;
for ind = 1:length(C)
if ~isempty(C{ind})
disp(['Processing C{' num2str(ind) '}']);
end
end
and never let index of C exceed length(C).
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