matlab coder - function with 'char switch' - matlab

Is something like this:
function [rv] = get_bla(m)
%#codegen
assert(isa(m,'char'));
assert(size(m, 1) >= 1);
assert(size(m, 1) <= 1024);
switch m
case 'xyz'
rv = 1;
case 'xyz1'
rv = 2;
otherwise
error('Unexpected something');
end
actually possible in the context of the matlab coder?
I am using:
codegen -config:dll get_bla
and get:
SWITCH expression has indeterminate size.
As 'char arrays' have to be of static size for C/C++, I presume the above is impossible or is there a work around?

Try using if-elseif statements instead of the switch statement.
if strcmp(m, 'xyz')
rv = 1;
elseif strcmp(m, 'xyz1')
rv = 2;
else
error('unexpected');
end

Related

How to print ONCE if there are multiple correct answers? (MATLAB)

So I have arr = randi([0,20],20,1). I want to show: If there are numbers less than 5, fprintf('Yes\n') only once. Im using a for loop (for i = 1 : length(arr)) and indexing it.
As your description, maybe you need if statement within for loop like below
for i = 1:length(arr)
if arr(i) < 5
fprintf('Yes\n');
break
end
end
If you want to print Yes once, you can try
if any(arr < 5)
fprintf('Yes\n')
endif
If you don't want to use break, the code below might be an option
for i = 1:min(find(arr <5))
if (arr(i) < 5)
fprintf('Yes\n');
end
end
You can use a break statement upon finding the first value under 5 and printing the Yes statement.
Using a break Statement:
arr = randi([0,20],20,1);
for i = 1: length(arr)
if arr(i) < 5
fprintf("Yes\n");
break;
end
end
Extension:
By Using any() Function:
Alternatively, if you'd like to concise it down without the need for a for-loop the any() function can be used to determine if any values within the array meet a condition in this case arr < 5.
arr = randi([0,20],20,1);
if(any(arr < 5))
fprintf("Yes\n");
end
By Using a While Loop:
Check = 0;
arr = randi([0,20],20,1);
i = 1;
while (Check == 0 && i < length(arr))
if arr(i) < 5
fprintf("Yes\n");
Check = 1;
end
i = i + 1;
end

How to generalize Matlab function?

I have a Matlab function. I need to generalize this function. This code’s aim is to check this IndicMPs are in the TableTemp, if it is there, then we extract relevant age limits, such as: Age_Limite_DC, Age_Limite_IT, Age_Limite_Ch and Transfert_Prime_IT_DC. My idea is to generalize, passing parameters to find out the "Type_pret" is.(May be I'm wrong) Since I'm beginner to Matlab can someone help me to encode a more generic function that can be used in a more general context?
function Structure = optimisation_function()
Data = load('Data.mat');
Structure = Data.Structure;
TableTemp = Data.TableTemp;
Age_Limite_DC = zeros(size(Structure,1),1);
Age_Limite_IT = zeros(size(Structure,1),1);
Age_Limite_CH = zeros(size(Structure,1),1);
Transfert_Prime_IT_DC = zeros(size(Structure,1),1);
for IndexMPAL = 1 : length(Structure.AnneeSouscription)
% Determine Type_Pret (Loan Type)
if ~isempty(strfind(Structure.Type_Pret{IndexMPAL},'A'))
Type_Pret = 'A';
elseif ~isempty(strfind(Structure.Type_Pret{IndexMPAL},'B'))
Type_Pret = 'B';
elseif ~isempty(strfind(Structure.Type_Pret{IndexMPAL},'C'))
Type_Pret = 'C';
elseif ~isempty(strfind(Structure.Type_Pret{IndexMPAL},'D'))
Type_Pret = 'D';
elseif ~isempty(strfind(Structure.Type_Pret{IndexMPAL},'E'))
Type_Pret = 'E';
end
MP_CP = Structure.NomCodeProduit(IndexMPAL);
MP_AnSous = Structure.AnneeSouscription(IndexMPAL);
MP_TypePret = Type_Pret;
IndicCP = strcmp(MP_CP, TableTemp.CodeProduit);
IndicAS = MP_AnSous== TableTemp.AnneeSouscription;
IndicTP = strcmp(MP_TypePret, TableTemp.TypePret);
IndicMP = IndicCP & IndicAS & IndicTP;
if ~any(IndicMP)
Msg = strcat('CodeProduct:',MP_CP{1}, ', Année Souscription:', num2str(MP_AnSous), ', Type Prêt:', MP_TypePret);
error('Error', Msg)
else
Age_Limite_DC(IndexMPAL,1) = TableTemp.Age_Limite_DC(IndicMP,1);
Age_Limite_IT(IndexMPAL,1) = TableTemp.Age_Limite_IT(IndicMP,1);
Age_Limite_CH(IndexMPAL,1) = TableTemp.Age_Limite_CH(IndicMP,1);
Transfert_Prime_IT_DC(IndexMPAL,1)=
TableTemp.Transfert_Prime_IT_DC(IndicMP,1);
end
end
Structure.Age_Limite_DC = Age_Limite_DC;
Structure.Age_Limite_IT = Age_Limite_IT;
Structure.Age_Limite_CH = Age_Limite_CH;
Structure.Transfert_Prime_IT_DC = Transfert_Prime_IT_DC;
end
The if/elseif can be simplified with a cell array:
liststr = {'A','BB','C','D','E'}; % builds a cell array, each cell contains a string
Positive_matches = strfind(liststr,Structure.Type_Pret{IndexMPAL}) % returns a list for each cell of the indices where the element was found (empty if none)
Index = find(~cellfun('isempty', Positive_matches )) % converts the previous list into a logical 0/1 array indicating whether an item was found (1) or not (0)
% if isempty(Index); continue; end % If no index is found, to avoid an error in the next instruction, skips the rest of the code.
Type_Pret = liststr(Index(1));
If the Type_Pret are the same in your list and in Structure? , you can usestrcmp`:
liststr = {'A','B','C','D','E'};
if any(strcmp(Structure.Type_Pret,liststr))
Type_Pret = Structure.Type_Pret
else
% handle error
end
You can also work directly on Structure.Age_Limite_DC without using Age_Limite_DC.

matlab oop "use data of hole class" for calculation

First, sorry for the bad title - I'm new to OO programming - basically I'd like to understand how Matlab works with oop classes.
Before I ask my question, here is a basic example of what I want to do:
I have two houses and some data about them and I got the idea, to work with oop classes. Here is my .m file.
classdef building
properties
hohe = 0;
lange = 0;
breite = 0;
xabstandsolar = 0;
yabstandsolar = 0;
end
methods
function obj = building(hohe, lange, breite, xabstandsolar, yabstandsolar)
obj.hohe = hohe;
obj.lange = lange;
obj.breite = breite;
obj.xabstandsolar = xabstandsolar;
obj.yabstandsolar = yabstandsolar;
end
function hohenwinkel(h)
h = h
d = sqrt(obj.xabstandsolar^2 + yabstandsolar^2);
gamma_v = atand((obj.hohe - h)/(d));
end
end
end
I filled it with some data - for example
>>H1 = building(10,8,6,14,8)
>>H2 = building(18,8,6,14,0)
And now I want to calculate "gamma_v" (as an 1x2 array) for each building. Any ideas, how I can archive this?
Edit:
I want to create gamma_v (as an array) automatically for all objects in the class "building". There will be a lot more "houses" in the final script.
Your hohenwinkel method needs to accept two input arguments. The first argument for non-static methods is always the object itself (unlike C++, you'll have to explicitly list it as an input argument) and the second input will be your h variable. You'll also want to actually return the gamma_v value using an output argument for your method.
function gamma_v = hohenwinkel(obj, h)
d = sqrt(obj.xabstandsolar^2 + obj.yabstandsolar^2);
gamma_v = atand((obj.hohe - h)/(d));
end
Then you can invoke this method on each building to get the value
gamma_v1 = hohenwinkel(H1);
gamma_v2 = hohenwinkel(H2);
If you want to have an array of buildings, you can create that array
houses = [building(10,8,6,14,8), building(18,8,6,14,0)];
gamma_v = hohenwinkel(houses);
and then construct your hohenwinkel function to operate on each one and return the result
function gamma_v = hohenwinkel(obj, h)
if numel(obj) > 1
% Compute hohenwinkel for each one
gamma_v = arrayfun(#(x)hohenwinkel(x, h), obj);
return
end
d = sqrt(obj.xabstandsolar^2 + obj.yabstandsolar^2);
gamma_v = atand((obj.hohe - h)/(d));
end
there is some tricky solution (and its not recommended)(#Suever solution is better)
you should create a handle class
classdef gvclass<handle
properties
gvarr=[];
end
methods
function setgvarr(obj,value)
obj.gvarr=[obj.gvarr,value];
end
end
end
then use this class in your building class
classdef building<handle
properties
gv
hohe = 0;
lange = 0;
breite = 0;
xabstandsolar = 0;
yabstandsolar = 0;
end
methods
function obj = building(hohe, lange, breite, xabstandsolar, yabstandsolar,handle_of_your_gv_class,h)
obj.hohe = hohe;
obj.lange = lange;
obj.breite = breite;
obj.xabstandsolar = xabstandsolar;
obj.yabstandsolar = yabstandsolar;
obj.gv=handle_of_your_gv_class;
obj.hohenwinkel(h);
end
function hohenwinkel(obj,h)
d = sqrt(obj.xabstandsolar^2 + yabstandsolar^2);
gamma_v = atand((obj.hohe - h)/(d));
obj.gv.setgvarr(gamma_v);
end
end
end
finally before creating any building you should create an object of gv class and pass it to the building constructor,
Egv=gvclass();
H1 = building(10,8,6,14,8,Egv,2)
H2 = building(18,8,6,14,0,Egv,3)
and to access gv array:
Egv.gvarr
you should do more effort on this issue to debug possible errors.

Matlab: two different variables take the same value

I want to implement recursion without a recursive function.
My code is the following:
for ff=1:6
for step=i:-1:1
if (step == maxStep)
R=-1;
if(isTM =='1')
R =1;
end
else
DielectricConst =cell2mat(valueArray(step,1));
Magnetic =cell2mat(valueArray(step,2));
currentFreq = cell2mat(frequencies(ff));
w = 2*3.1416*currentFreq;
kiz =w*(DielectricConst*Magnetic - E0*M0*sin(angle).*sin(angle))^(1/2);
DiConstPlusOne = cell2mat(valueArray(step+1,1));
MagPlusOne =cell2mat( valueArray(step+1,2));
kizPlusOne =w*(DiConstPlusOne*MagPlusOne - E0*M0*sin(angle).*sin(angle))^(1/2);
res =((DiConstPlusOne*kiz)-(DielectricConst*kizPlusOne))/((DiConstPlusOne*kiz)+(DielectricConst*kizPlusOne));
result =(res + R * exp(-((-1)^(1/2))*2*kizPlusOne*cell2mat( valueArray(step+1,3))))/(1+res*(R)*exp(-((-1)^(1/2))*2*kizPlusOne*cell2mat( valueArray(step+1,3))));
R=result;
end
% disp(R);
end
end
res and result values are always the same. Is it a pointer problem ?

I got error message about simulink "Output argument is not assigned on some execution paths"

In simulink, I made some model using "MATLAB function"block
but I met error message here.
here is code and error message.
function [VTAS,postVTAS]=fcn(mode,initialVTAS,a,t,preVTAS)
if mode == 1
VTAS = initialVTAS + (a * t) ;
postVTAS = VTAS;
elseif mode == 2
datasize = length(preVTAS);
lastvalue = preVTAS(datasize);
VTAS = lastvalue + 0;
postVTAS = VTAS;
end
end
Output argument 'VTAS' is not assigned on some execution paths.
Function 'MATLAB Function' (#36.25.28), line 1, column 26:
"fcn"
Launch diagnostic report.
I think there is no problem about output "VTAS"
please teach me what is a problems.
As the compiler tells you, under some circumstances there is no output value assigned to VTAS. The reason is that you only assign values to that output if mode is 1 or 2. The compiler doesn't know what values are feasible for mode. To remedy this, you need to make sure that VTAS is assigned under any and all circumstances.
This could be accomplished by, e.g. adding an else construct, like so:
function [VTAS,postVTAS]=fcn(mode,initialVTAS,a,t,preVTAS)
if mode == 1
VTAS = initialVTAS + (a * t) ;
postVTAS = VTAS;
elseif mode == 2
datasize = length(preVTAS);
lastvalue = preVTAS(datasize);
VTAS = lastvalue + 0;
postVTAS = VTAS;
else
VTAS = NaN;
postVTAS = NaN;
end
end
Edit:
Additionally, it would be good practice for the else case to throw an error. This would be helpful for debugging.
As a minor note, for every case, postVTAS is equal to VTAS, so essentially it is superfluous to return both from the function.