I have created an array of objects and I would like assign a property value in a vector operation without using a for loop. Unfortunately I get an error.
A simplified example of the problem.
classdef clsMyClass < handle
properties
dblMyProperty1
end
methods
function obj = clsMyClass()
end
end
end
And when running
vecMyArray = clsMyClass.empty(100,0);
vecMyArray(100) = clsMyClass;
vecMyArray.dblMyProperty1 = 1:100;
We get the following error:
??? Incorrect number of right hand side elements in dot name
assignment. Missing [] around left hand side is a likely cause.
Any help would be appreciated.
I see what you're trying to do now. Use disperse from the MATLAB File Exchange:
>> [vecMyArray.dblMyProperty1] = disperse(1:100);
>> vecMyArray(1).dblMyProperty1
ans =
1
>> vecMyArray(10).dblMyProperty1
ans =
10
You can use the deal function for exactly this purpose:
[vecMyArray.dblMyProperty1] = deal(1:100);
See: http://www.mathworks.com/company/newsletters/articles/whats-the-big-deal.html
Edit: No you can't, actually; that'll set them to all be the vector 1:100.
I think you'll find your answer here in "Struct array errors." Even though this is a class, similar rules apply.
Unfortunately missing [] is not the cause, since adding them causes more errors. The cause is that you cannot assign the same value to all fields of the same name at once, you must do it one at a time, as in the following code:
So you'll need:
for ii=1:100
vecMyArray(ii).dblMyProperty1 = ii;
end
I know it's not satisfying, but I think it at least helps us to definitively understand this error.
Related
I am trying to write a nested for loop in visual basic macro which runs on excel.
Here is my simplified code
Dim intVar(2) As Integer
For intVar(1) = 0 To 4
For intVar(2) = intVar(1) To 4
Var = Var + intVar(1) + intVar(2)
Next intVar(2)
Next intVar(1)
When I try to compile the code "For control variable already in use" compile error is thrown. Is there any solution for using array variables for For Loop or should I declare different variables for each For Loop?
There are some questions with the same tag but none of them for the array type control variables. If you help me I would be glad.
Thank you for your interest
I am using the following code to filter a large array:
var arrayOfSelectedRowDetails = self.projectRowDetails.filter(
{ $0.projectNumber == self.projectNumberArray[selectedRow] }
)
Normally the code runs fine and I have no issues. But in one scenario (after I have deleted some management objects from the persistent store) and then rerun the code I am getting a EXC_BAD_ACCESS (code = 1, address=0x0) error at runtime.
I have set a break and stepped through the runtime of this statement. It is a large array built from a core data entity (using a fetch statement) - and therefore takes a long time. When I step through the code over the first dozen or so indexes the code runs ok - when i remove the break and let it run it then presents the error.
Is it possible to println() from within the closure statement to assist with debugging? I have tried a number of different syntaxes and cannot get it to work.
Alternatively, is it possible to set an error capture statement within the closure so that the code ceases through a break or an abort() statement?
Fundamentally i am trying to identify the index of the array at the point that the error occurs so that I can get sufficient information to debug the delete function (which is where I think the error is). I do not seem to be able to ascertain the index from the info available to me when the error occurs.
This is the first time I have tried programming in Swift and making use of closures so I am learning as I go. Apologies if I am asking fundamental questions. I have not been able to find a similar question elsewhere here with an answer that works.
You can set an exception breakpoint in Xcode (for an example see here).
Also, I suggest that you move the access to self.projectNumberArray out of the closure:
let pn = self.projectNumberArray[selectedRow]
var arrayOfSelectedRowDetails = self.projectRowDetails.filter(
{ $0.projectNumber == pn }
)
The change might not solve the issue, but it will at least help the debugging.
Lastly, if you want to print the index, the following approach will probably work:
let pn = self.projectNumberArray[selectedRow]
var index = 0
var arrayOfSelectedRowDetails = self.projectRowDetails.filter(
{ println(index++); return $0.projectNumber == pn }
)
I have a SWIG generated R wrapper which contains the following setClass operations:
setClass('_p_f_p_struct_parameters_p_struct_chromosome_p_struct_dataSet__double',
prototype = list(parameterTypes = c('_p_parameters', '_p_chromosome', '_p_dataSet'),
returnType = '_p_f_p_struct_parameters_p_struct_chromosome_p_struct_dataSet__double'),
contains = 'CRoutinePointer')
setClass('_p_f_p_struct_parameters_p_p_struct_chromosome_p_p_struct_chromosome_int_int__void',
prototype = list(parameterTypes = c('_p_parameters', '_p_p_chromosome', '_p_p_chromosome', '_int', '_int'),
returnType = '_p_f_p_struct_parameters_p_p_struct_chromosome_p_p_struct_chromosome_int_int__void'),
contains = 'CRoutinePointer')
These operation do not appear to be behaving as expected. When I call a function with the output being the creation of a _p_parameters object (defined above), I get the following error:
Error in getClass(Class, where = topenv(parent.frame())) :
“_p_parameters” is not a defined class
The setClass therefore seems to be not doing it's thing.
I tried to manually set the _p_parameters class via:
p_parameters<-setClass(Class="_p_parameters", representation = representation(ref = "externalptr"))
But this does not seem to work as when I try and modify other parameters (or even print parameters via an inbuilt function) the terminal crashes and hangs.
For reference, the final lines in initialiseParameters (the function which initially own _p_parameters) are calling the native C function via .Call then assigning the external pointer to a new object of class _p_paramters as follows:
;ans = .Call('R_swig_initialiseParameters', numInputs, numNodes, numOutputs, arity, as.logical(.copy), PACKAGE='cgp');
ans <- new("_p_parameters", ref=ans) ;
I've read various R doc on new(), setClass, S3/S4 classes but nothing seems to clarify what I'm meant to be doing here.
Any suggestions on where to start or tutorials that would give a good heads up would be most welcome.
Please keep in mind the C code is not mine (but is freely available under GNU), I am not a C programmer and am only weakly-moderately proficient in R. So please be gentle :)
Cheers.
PS: If I call the function in R terminal via .Call it works as expected (so it doesn't seem to e a C function error)
I thought I should post the solution I have to this. The least I could do for a 'tumbleweed' medal haha.
The only solution I could find to this is to comment out the following line:
ans <- new("_p_parameters", ref=ans) ;
in all function that try to create an R object.
The resulting memory pointer is then assigned to an R object at function call.
It's dirty, but I couldn't work out how to create an object from a memory pointer (at least from within the functions themselves).
It seems to work so I guess it will do.
I've used this website for many things and found a lot of useful information that has helped me create a randomized quiz mostly. I'm trying to make the code as efficient as possible and that has led me to this error.
I have created an array which uses the .push function to store existing buttons on the stage into the array for future use. The code shown below sets the label of each button correctly.
_buttons[0].label = xmlData.difficulty1.questions[num2].op1.text();
_buttons[1].label = xmlData.difficulty1.questions[num2].op2.text();
_buttons[2].label = xmlData.difficulty1.questions[num2].op3.text();
_buttons[3].label = xmlData.difficulty1.questions[num2].op4.text();
So naturally I wanted to make this a little more efficient and put these in a loop. Based on the logic this SHOULD work but doesn't.
for (var i:Number = 0; i < 4; i++)
{
_buttons[i].label = xmlData.difficulty1.questions[num2].op[i+1].text();
}
This code should simply increment the array counter of _buttons and set the label for each. I mean it's simply the first set of code in a for loop right? However when I run it I get the following error: TypeError: Error #1010: A term is undefined and has no properties.
Now I know for sure that the first set of code works as I have tested it repeatedly but as soon as I decide to put it into that for loop, it fails. Could anyone explain why? Perhaps it's a limitation of the language itself? Maybe I'm missing a command?
Try :
for (var i:Number = 0; i < 4; i++)
{
_buttons[i].label = xmlData.difficulty1.questions[num2]['op'+(i+1)].text();
}
.op[i+1] tries to access a property called 1 under a field called op instead of op1
Im trying to store values from radialspeed (a function from the phased array toolbox) into an array, but im getting errors:
Conversion to cell from double is not possible.
Error in modelCar (line 40)
Cell(1,T)= Rspeed;
^^Error Message
Cell = cell(1,12)
for T = 1:11
[POS,v] = step(H,T);
Rspeed = radialspeed(POS,v,[25; 25; 70],[0; 0; 0]);
typecast(Rspeed,'uint16');
Cell(1,T)= Rspeed;
%%Rspeed = Vel.Radspeed(:,T);
disp(Rspeed);
end
^^^Excerpt of the code im using.
Another question any tips to plot a graph continuously while in the loop, the draw now function doesn't seem to work
Thank you.
You should not use Cell as a variable since cell is reserved keyword in MATLAB. Though using Cell will pose no problems, but a simple typing mistake can inject errors into your code. You may use myCell, R_cell etc.
By writing, Cell(1,T)= Rspeed you are trying to assign Rspeed of type double to a cell datatype. You should write Cell{1,T}=Rspeed or Cell{T}=Rspeed. You can also visualize your output for each iteration as follows:
Replace disp(Rspeed) by:
hold on;scatter(T,Rspeed,'ro');
pause(0.001);
1st question: Cell(1,T) will return a cell so you need to change your code to Cell{T}= Rspeed;.
2nd question: recall plot is a possible solution if speed is not a main concern.