I have enabled dynamic memory allocation in Simulation Target>Advanced with default threshold as 0. Then I attempt to run this code:
B={{nan}}; %%Defining so that it can be set as size variable.
coder.varsize('B',[50 1]);
B={B;bwboundaries(BW,'noholes')} %%Not B{:}=bwboundaries() as multiple inputs are not allowed
Y=B{2}
boundary=Y{2}
This is the error message:
=== Simulation (Elapsed: 1:21 min) ===
Error:Simulink does not have enough information to determine output sizes for this block. If you think the errors below are inaccurate, try specifying types for the block inputs and/or sizes for the block outputs.
Error:This assignment writes a 'cell' value into a 'double' type in element '{1}{1}'. Code generation does not support changing types through assignment. Check preceding assignments or input type specifications for type mismatches.
Function 'Image Processing System/corner_detection' (#95.612.613), line 21, column 1:
"B"
Launch diagnostic report.
Error:Errors occurred during parsing of MATLAB function 'flightControlSystem/Image Processing System/corner_detection'
Error:Simulink cannot determine sizes and/or types of the outputs for block 'flightControlSystem/Image Processing System/corner_detection' due to errors in the block body, or limitations of the underlying analysis. The errors might be inaccurate. Fix the indicated errors, or explicitly specify sizes and/or types for all block outputs.
Error:Simulink cannot determine sizes and/or types of the outputs for block 'flightControlSystem/Image Processing System/corner_detection' due to errors in the block body, or limitations of the underlying analysis. The errors might be inaccurate. Fix the indicated errors, or explicitly specify sizes and/or types for all block outputs.
How can I modify the code so it works?
Related
I have a function in matlab calculating something. Within that function I open another function to calculate something for it.
Now in this second function I have some case where I just want to stop everything if some certain condition is true (so I want to end both functions)
I don't want an error message or anything; Is there a command for that?
If I just type in error I get some notice in red with a message such as:
error: Invalid call to error. Correct usage is:
-- Built-in Function: error (TEMPLATE, ...)
-- Built-in Function: error (ID, TEMPLATE, ...)
error: called from:
error: /usr/share/octave/3.8.1/m/help/print_usage.m at line 89, column 5
>>>error: /home/john/wpq.m at line 75, column 4
error: /home/john/test.m at line 23, column 21
if I write error('blabla') I still get:
>>>error: blabla
error: called from:
error: /home/john/wpq.m at line 75, column 4
error: /home/john/test.m at line 23, column 21
I would like to get no output because I can write one line above already something like disp('the test on this number failed').
You could try placing a try/catch block in your main function to expect the condition under which you want code execution to stop.
I don't believe that there is any one command that allows code to stop execution from a function within a function.
There are a number of ways of doing what you want. Typically error is only meant to be used for things that actually is errors. You do for example get an "index out of bounds" error if you try to access an element outside the array. In case what happens is an error you should send an error message to inform users about what happens and highlight that this is an error. However, in case you only want this particular calculation to end and not the program I would instead recommend try-catch and printing the error message in catch.
In case this is normal termination (or if only a particular function terminates unnormally and this is expected for some input) you can either use a termination condition (function [out,success] = myFun(in)) or try-catch. Both are accepted, though I use to prefer the termination condition approach for normal termination and try-catch for unnormal termination (of functions). Unnormal termination can for example be when a function have to be terminated before all output variables are calculated. I use to prefer to have an exception thrown instead of a function returning invalid values (but a c-programmer would probably argue differently).
For the record, there is a return-statement in Matlab which terminates a particular function.
It is hard to recommend a particular approach without knowing the situation you are in, but this text would give you some different options to be choose between. Know that error handling seldom have standard approaches which can be said to be "right". It is often up to the programmer to decide what is suitable and that is typically a part of the design.
Good luck!
I'm building my first s-function block from compiled C code. Everything is going fine, except that the s-function block demands that its interface variables are of type double, even though the underlying C interface variables are not. The block raises an error if I connect a boolean signal to the input and try to run.
I'm getting the variables in the code by calling ssGetInputPortSignal and ssGetOutputPortSignal, and casting the void pointers they return into the correct pointer types.
How do I configure the types of an s-function block's parameters in Simulink?
Take a look at ssSetInputPortDataType. Needs to be called in the S-Function mdlInitializeSizes function. In your case you'll need something like:
ssSetInputPortDataType(S, 0, SS_BOOLEAN);
Assuming the input port is the first one and you're not concerned about the return value.
The function for the outputs is ssSetOutputPortDataType, with identical use.
I stumbled over a particular problem with interfaces while debugging some code, where a called subroutine has a dummy argument of rank 2 but an actual argument of rank 1. The resulting difference in the arguments resulted in an invalid read.
To reproduce I created a small program (ignore the comments ! <> for now):
PROGRAM ptest
USE mtest ! <>
IMPLICIT NONE
REAL, ALLOCATABLE, DIMENSION(:) :: field
INTEGER :: n
REAL :: s
n = 10
ALLOCATE(field(n))
CALL RANDOM_NUMBER(field)
CALL stest(n, field, s)
WRITE(*,*) s
DEALLOCATE(field)
END PROGRAM
and a module
MODULE mtest ! <>
IMPLICIT NONE ! <>
CONTAINS ! <>
SUBROUTINE stest(n, field, erg)
INTEGER :: n
REAL, DIMENSION(n,n) :: field
REAL :: erg
erg = SUM(field)
END SUBROUTINE
END MODULE ! <>
As far as I understand, this subroutine gets an automatic (explicit?) interface from being placed in the module. The problem is, that the actual field has length 10, while the subroutine sums a field of length 10x10=100 which is clearly visible in valgrind as an invalid read.
Then I tested this same code without the module, i.e. all lines marked with ! <> got removed/commented. As a result, gfortran's -Wimplicit-interface threw a warning, but the code worked as before.
So my question is: What is the best way, to deal with such a situation? Should I always place a generic interface à la
INTERFACE stest
MODULE PROCEDURE stest
END INTERFACE
in the module? Or should I replace the definition of field with an deferred-shape array (i.e. REAL, ALLOCATABLE, DIMENSION(:,:) :: field)?
EDIT: To be more precise on my question, I don't want to solve this particular problem, but want to know, what to do, to get a better diagnostic output from the compiler.
E.g. the given code doesn't give an error message and does, in principle, produce a segmentation fault (though, the code doesn't notice it). Placing a generic interface produces at least an error, complaining, that no matching definition for stest is found, which is also not really helpful, especially in the case, where you don't have the source code. Only a deferred-shape array resulted in an understandable error message (rank mismatch).
And this is, were I'm wondering, why the automatic module interface doesn't give a similar warning/error message.
The compiler cannot warn you, because the code is legal! You just pass wrong n and a non-square number of points. For explicit shape arrays you are responsible for correct dimensions. Consider
ALLOCATE(field(1000))
CALL stest(10, field, s)
this code will work although the number of elements of the actual and dummy arguments is not the same. Maybe suggest to gfortran developers to check whether the dummy argument is not larger, but I am not sure how difficult that is.
The generic interface causes the compiler to check the TKR rules. No sequence association of arrays of different rank is allowed and the compilation will fail. Therefore it will disable all legal uses of passing arrays of different rank to explicit shape and assumed size dummy arguments and limit your possibilities.
What is the solution? Use explicit shape arrays for situations they are good for and use assumed shape arrays otherwise (possibly with the contiguous attribute). The generic interface might help too, but changes the semantics and limits the possible use.
[~,col] = find(ocpRefPt(2,:)>x1 & ocpRefPt(2,:)<x2 & ocpRefPt(1,:)>y1 & ocpRefPt(1,:)<y2);
About is the line where the compilation fails. The above line is in a loop.
x1,x2,x3,x4 are scalars(natural numbers)
ocpRefPt is a 2x16 matrix
Error: FIND requires variable sizing
What does this mean. How to overcome this error?
So it seems that you are trying to compile with emlmex to make embedded code. The error is saying that the size of the output of find is not known, and apparently the compiler requires fixed size outputs. See this newsgroup post for one explanation.
This method of compilation seems to be obsolete -- use the MATLAB coder (codegen command) instead:
emlmex Generate a C-MEX file from MATLAB code.
emlmex [-options] fun1 [fun2 ...]
This function is obsolete. For general purpose acceleration
and code generation use CODEGEN.
There are different data types in SystemVerilog that can be used like the following:
reg [31:0] data;
logic [31:0] data;
bit [31:0] data;
How do the three of them differ?
reg and wire were the original types. Wires are constantly assigned and regs are evaluated at particular points, the advantage here is for the simulator to make optimisations.
wire w_data;
assign w_data = y;
// Same function as above using reg
reg r_data;
always #*
r_data = y ;
A common mistake when learning Verilog is to assume the a reg type implies a register in hardware. The earlier optimisation for the simulator can be done through the context of its usage.
This introduces logic which can be used in place of wire and reg.
logic w_data;
assign w_data = y;
// Same function as above using reg
logic r_data;
always #*
r_data = y ;
The type bit and byte have also been created that can only hold 2 states 0 or 1 no x or z. byte implies bit [7:0]. Using these types offers a small speed improvement but I would recommend not using them in RTL as your verification may miss uninitialized values or critical resets.
The usage of bit and byte would be more common in testbench components, but can lead to issues in case of having to drive x's to stimulate data corruption and recovery.
Update
At the time of writing I was under the impression that logic could not be used for tristate, I am unable to find the original paper that I based this on. Until further updates, comments or edits, I revoke my assertion that logic can not be used to create tri-state lines.
The tri type has been added, for explicitly defining a tri-state line. It is based on the properties of a wire, logic is based on the properties of a reg.
tri t_data;
assign t_data = (drive) ? y : 1'bz ;
If you no longer have to support backwards compatibility Verilog then I would recommend switching to using logic and tri. Using logic aids re-factoring and and tri reflects the design intent of a tristate line.
The choice of the name reg turned out to be a mistake, because the existence of registers is instead inferred based on how assignments are performed. Due to this, use of reg is essentially deprecated in favor of logic, which is actually the same type.
logic is a 1-bit, 4-state data type
bit is a 1-bit, 2-state data type which may simulate faster than logic
If a logic is also declared as a wire, it has the additional capability of supporting multiple drivers. Note that by default wire is equivalent to wire logic.
In general, the "nets" (such as wire and tri) are most suitable for designing communication buses.
Practically speaking, for RTL it usually doesn't matter whether you declare with reg, or logic, or wire. However, if you have to make an explicit declaration of a 4-state type (as opposed to when you don't), you should typically choose logic since that is what is intended by the language.
Related articles:
What’s the deal with those wire’s and reg’s in Verilog
An analysis of the "logic" data type by Cliff Cummings - 20021209
As I'm unable to add a comment I've to write what looks like a new answer but isn't. Sigh!
#e19293001, #Morgan, logic defines a 4-state variable unlike bit, and hence a logic variable can be used to store 1'bz so the following code is valid and compiles:
logic t_data;
assign t_data = (drive) ? y : 1'bz ;
But I agree that to reflect the design intent tri should be used instead of logic in these cases (although I must say I don't see people using tri instead of logic/wire too often).
reg and logic are exactly the same. These data types appear inside the always or initial blocks and store values i.e. always #(a) b <= a;, the reg b gets evaluated only when 'a' changes but otherwise it simply stores the value it has been assigned last.
wire are just simply connections and need to continuously driven. I agree that they can behave identical as #Morgan mentioned, but they can be imagined as a piece of hard wire, the value of which changes only the value at the other end or the source changes.
How do the three of them differ?
There is no difference between logic and reg.
The difference between bit and the other two is that bit is 2-state, whereas logic/reg are 4-state.
Refer to IEEE Std 1800-2017, section 6.11.2, 2-state (two-value) and 4-state (four-value) data types:
logic and reg denote the same type.
Also, section 6.3.1 Logic values:
The SystemVerilog value set consists of the following four basic values:
0 —represents a logic zero or a false condition
1 —represents a logic one or a true condition
x —represents an unknown logic value
z —represents a high-impedance state
Several SystemVerilog data types are 4-state types, which can store
all four logic values. All bits of 4-state vectors can be
independently set to one of the four basic values. Some SystemVerilog
data types are 2-state, and only store 0 or 1 values in each bit of a
vector.
Logic data type doesn't permit multiple driver. The last assignment wins in case of multiple assignment .Reg/Wire data type give X if multiple driver try to drive them with different value. Logic data type simply assign the last assignment value.
The "Reg" data type is used in procedural assignment, whereas the "Logic" data type can be used anywhere.