Matlab making new cell array from another cell array fileds - arrays

I have a cell array thiscells:
thiscells <1*40 cell>
eacharray of thiscells is 280*3
I have a function (TheFunction) that gets input of cell array that each array is X*2
How can I send a cell array to TheFunction that contain only columns1,3 from each array?
I tried
TheFunction(thiscells{:}(:,1:2)) % tring to send only columns 1,2
But it didn't work
Edit:
working with (but still looking for faster way to do so):
What is did so far
TheFunction(makingNewCells(thiscells,2));
when
makingNewCells:
[newCells]=makingNewCells(oldCells)
for ii=1:max(size(oldcells))
newCells=oldCells(:,[1 column]);
end

This question and its answers may be of help - thiscells{:}(:,1:2) is already failing without the call to Thefunction, if I am not mistaken.
For cells, the problem is even worse: add to this impossibility to double-subref that even if it did what you intended it to do, this passes 40 arguments (which are all 280x2 vectors) to Thefunction. I doubt there are (m)any legitimate uses for a function that takes 40 arguments of the same type, instead of having those wrapped in a cell. I would probably try doc cellfun first.
EDIT: just to be clear, I suggest changing Thefunction so that it accepts a cell of 40 matrices of size 280x2), then using
cell_of_twocolumned_arrays = cellfun(#(x)x(:,[1 2]),thiscells)

Related

How do I replace an array element in LabView? (2d array of pictures)

so I have a final project for a class where I need to make a video game in LabView. The issue I'm having at the moment is that I can't figure out the 'right' way to put 'yourShip.png' into the 2d array of 2d pictures at [0,0]. Every tutorial I can find basically has exactly what I have down below in the screenshot, and it makes sense to me. However, running the program quickly shows that it does nothing.
To describe the code, I have a path constant that leads to the picture, which feeds to a draw flattened pixelmap function. Up to this point I know the code works, since creating a test indicator reveals as such. However, next I try to use the replace array subset function to replace the (default blank) 2d picture at [0,0] with yourShip.png. 'screen' is a 5x5 2d array of 2d pictures. The local variable of the same name being outputted to is indeed the very same array.
My main guess with why my code doesn't work is because of the way I'm taking screen as the input variable and then outputting to it via a local variable. However, if this is wrong, I'm confused with how I should do it. All I want to do is 'spawn' the image at the correct index.
The replace array subset works quite literally, i.e. it can only replace existing elements.
If there is no element at the specified index because the array is smaller, the function will do just nothing.
I guess your array is empty, so, initialize your screen array first to a size of at least 1x1.

Using jsonencode with length 1 array

When using the MATLAB jsonencode function it seems very difficult to convert size 1 arrays into the correct JSON format i.e. [value]. For example if I do:
jsonencode(struct('words', [string('hello'), string('bye')]))
Then this produces:
{"words":["hello","bye"]}
which is correct. If however I do:
jsonencode(struct('words', [string('hello')]))
Then it produces:
{"words":"hello"}
losing the square brackets, which it needs because it is in general an array. The same happens when using a cell rather than an array, although using a cell does work if it's not inside a struct.
Any idea how I can work around this issue?
It seems this can be solved by using a cell rather than an array and then not creating the struct inline. Like
s.words = {'hello'};
jsonencode(s)
Output:
{"words":["hello"]}
I presume when created inline the cell functionality of matlab is actually trying to make multiple structs rather than multiple strings. Note that this still won't work with arrays as matlab treats a size one array as a scalar.

Array constant in a formula with non-adjacent cell references

I need to add an array of non-adjacent cells to my array formula. I have tried all of the following array constant-like ways and they all give me a "There is a problem with this formula error".
'Chart Data'!{A12:A14,D3:D11}
{'Chart Data'!A12:A14,'Chart Data'!D3:D11}
'Chart Data'!{A12,A13,A14,D3:D11}
{'Chart Data'!A12,'Chart Data'!A13,'Chart Data'!A14,'Chart Data'!D3:D11}
'Chart Data'!{A12,A13,A14,D3,D4,D5,D6,D7,D8,D9,D10,D11}
{'Chart Data'!A12,'Chart Data'!A13,'Chart Data'!A14,'Chart Data'!D3,'Chart Data'!D4,'Chart Data'!D5,'Chart Data'!D6,'Chart Data'!D7,'Chart Data'!D8,'Chart Data'!D9,'Chart Data'!D10,'Chart Data'!D11}
Entire formula (the array constant goes where the {#####} is):
{=SUM(((1-References!M1:M12)*({#####}*(G3:G14+F3:F14-0.11)))+((References!M1:M12)*('Chart Data'!A12:A23*(G3:G14+F3:F14-0.11)))+((H2:H13*X3:X14)+(H3:H14*Y3:Y14)+(I2:I13*(V3:V14-X3:X14))+(I3:I14*(W3:W14-Y3:Y14))))}
I am 100% positive that it is this particular array constant that is causing the problem. I can't move the cells I'm referencing to put them in line. Is it even possible to reference a non-adjacent range in an array formula? If it's possible, what am I doing wrong?
There are several ways to do this. The following is very simple and pretty direct so my favorite.
EITHER choose a cell to build your string for your non-contiguous array in OR create a Named Range to do it. I'll show the first as it seems nicest for being able to use the mouse freely, but in both of them you can actually be creative using about how you build the string that will become your array. The main advantage of creating it in a Named Range is no helper cell lying about anywhere.
So, you create that string and then make it an array. Say you have a non-contiguous array needed using cells A12:A14 and C3:C11. You use joining and TEXTJOIN() like so:
="{"&TEXTJOIN(",",FALSE,B12:B14,C3:C11)&"}"
to create a text string of the values in those cells wrapped with the curly braces ({}) just as if you'd typed it in ("hardcoded it"). It will look like this with the right values in those cells:
{1,2,3,1,2,3,4,5,6,7,8,9}
but is ain't an array yet.
Now the magic in THIS method. Create a Named Range, perhaps called String2Array, and give it a formula of:
=EVALUATE(A1)
(or whatever cell you used for the above formula creating the text string that you want to be an array). Make the reference absolute. ($A$1... which it will do for you, just don't edit it to be relative. If you use this for similar work, but need it relative, that will work fine, but it just isn't what is needed here.)
Now replace your placeholder in the formula with the Named Range's name (perhaps you DID use String2Array). And you're done.
A couple other methods use INDEX() or CHOOSE() and you can force things to be arrays using the functions DOLLARDE() and IMREAL() (I found on a helpsite in a 2014 post) and some others do the same kind of thing. In those days, one had to use {CSE} too, but SPILL takes care of that now (with those two weird-seeming friendlies and at least two others). The poster was someone I've seen on this site, EXCELXOR was the name for the site, XOR LX was the name of the member here though the functions were mentioned in a comment by a Lori. Since he covers, it seems, aspects not usually covered in helpsites, looking up some of his work here, or elsewhere too, might be worthwhile to some folks.
But this method is very direct and therefore easy to maintain. And personally, I love the idea that EVALUATE() (must be used IN the Named Range functionality, not cell-side) is the gift that keeps on giving, one wonderfully helpful thing after another.
So many ways. You could even literally build the array in a helper column/row somewhere and reference THAT instead of the non-contiguous addresses. I like the joining+TEXTJOIN() approach best because I can use the mouse to easily get all the blocks into the formula since it is a LIVE formula. But you can type out a string fairly easily too and add the {}'s. Or perhaps a user would type a string of addresses and you'd add them like the formula does above. And you can insert actual values (constants) into the string you are building as well if that is appropriate. And you could build it formulaicly... I wouldn't pick that workload first thing off the pile of choices, but if you were going to do it anyway already, then... or if it's a small build.

Array (class) filled with non nil values stays empty

I am currently having trouble filling up an array of customClass.
I try to fill it with a jsonFile. During my json parsing (using swiftyJSON) i loop and fill my array.
The problem is, at the end of my loop, it is still empty. I tested it in different ways, and here is my code:
That's the file where the problem is. In my loop I fill an Annotation, that I add with append to my array. The problem is what my print return. Here is a part of it:
It's just a small part of a huge jsonfile. And, my tmpAnnot.name is correctly printed every iteration. But when it comes to my Array, nothing.
So I'm completly lost and hope you could help me ^^
(And for the information, here is my custom class) :
And btw, I tried to print my array.count, and it's nil too
Im so sorry if the question has been posted. I couldn't find it in the entire website.
Change your JSONAnnotationList declaration to be an non-optional and assign it an empty array
var JSONAnnotationList: [UGOAnnotation] = []
You see, you have never created an array so there was nothing to be printed.
The whole point of optionals is to use them sparingly, not everywhere.

How to copy cell to array in Matlab

Alright let me explain detailed my question
this below image is displaying my matrix where i want to copy my data
Alright now what i want to do that is as you can see 1x4 cell
i want to copy it as an array to another variable such as
input_values=ones(1,4);%init
input_values=input_matrix_training(1);
So at the above i am trying to copy the elements in that cell array which is row 1 to the input_values array. But if i do as i above i am getting this instead of the values that array contains. ty
instead of above it should be like
The other values are a cell, and are thus best referenced with {} instead of (). Also, sometimes they need to be wrapped into [], depending on the format. Plus the fact that you don't need to initialize input_values, and what you should do becomes this:
input_values=[input_matrix_training{1}];
Or you can just use cell2mat
input_values=cell2mat(input_values(1));

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