I'm new to Matlab and now learning the basic grammar.
I've written the file GetBin.m:
function res = GetBin(num_bin, bin, val)
if val >= bin(num_bin - 1)
res = num_bin;
else
for i = (num_bin - 1) : 1
if val < bin(i)
res = i;
end
end
end
and I call it with:
num_bin = 5;
bin = [48.4,96.8,145.2,193.6]; % bin stands for the intermediate borders, so there are 5 bins
fea_val = GetBin(num_bin,bin,fea(1,1)) % fea is a pre-defined 280x4096 matrix
It returns error:
Error in GetBin (line 2)
if val >= bin(num_bin - 1)
Output argument "res" (and maybe others) not assigned during call to
"/Users/mac/Documents/MATLAB/GetBin.m>GetBin".
Could anybody tell me what's wrong here? Thanks.
You need to ensure that every possible path through your code assigns a value to res.
In your case, it looks like that's not the case, because you have a loop:
for i = (num_bins-1) : 1
...
end
That loop will never iterate (so it will never assign a value to res). You need to explicitly specify that it's a decrementing loop:
for i = (num_bins-1) : -1 : 1
...
end
For more info, see the documentation on the colon operator.
for i = (num_bin - 1) : -1 : 1
Related
I have a question about removing duplicates in a table (rexx language), I am on netphantom applications that are using the rexx language.
I need a sample on how to remove the duplicates in a table.
I do have a thoughts on how to do it though, like using two loops for these two tables which are A and B, but I am not familiar with this.
My situation is:
rc = PanlistInsertData('A',0,SAMPLE)
TABLE A (this table having duplicate data)
123
1
1234
12
123
1234
I need to filter out those duplicates data into TABLE B like this:
123
1234
1
12
You can use lookup stem variables to test if you have already found a value.
This should work (note I have not tested so there could be syntax errors)
no=0;
yes=1
lookup. = no /* initialize the stem to no, not strictly needed */
j=0
do i = 1 to in.0
v = in.i
if lookup.v <> yes then do
j = j + 1
out.j = v
lookup.v = yes
end
end
out.0 = j
You can eliminate the duplicates by :
If InStem first element, Move the element to OutStem Else check all the OutStem elements for the current InStem element
If element is found, Iterate to the next InStem element Else add InStem element to OutStem
Code Snippet :
/*Input Stem - InStem.
Output Stem - OutStem.
Array Counters - I, J, K */
J = 1
DO I = 1 TO InStem.0
IF I = 1 THEN
OutStem.I = InStem.I
ELSE
DO K = 1 TO J
IF (InStem.I ?= OutStem.K) & (K = J) THEN
DO
J = J + 1
OutStem.J = InStem.I
END
ELSE
DO
IF (InStem.I == OutStem.K) THEN
ITERATE I
END
END
END
OutStem.0 = J
Hope this helps.
I'm quite new to Matlab so excuse me for the basic question.
I need to make a for-loop that repeats it's self 384 times.
So :
for i=1:384
I now need the for loop to check if 2 certain variables have the value 1 through 10, and then let them store this in a new variable with that value.
So:
if x==1
somevariable = 1
elseif x== 2
saomevariable = 2
..
..
..
elseif y = 1
someothervariable = 1
etc etc.
Is there a way to write this more efficient?
Thank you!
The first think you can do is:
if(x >= 1 && x <= 10)
somevariable=x;
end
if(y >= 1 && y <= 10)
someohtervariable=y;
end
If you could post more information about "x" and "y", perhaps your script can be further "improved".
Hope this helps.
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 ?
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.
Is it somehow possible to concatenate two matlab structures recursively without iterating over all leaves of one of the structures.
For instance
x.a=1;
x.b.c=2;
y.b.d=3;
y.a = 4 ;
would result in the following
res = mergeStructs(x,y)
res.a=4
res.b.c=2
res.b.d=3
The following function works for your particular example. There will be things it doesn't consider, so let me know if there are other cases you want it to work for and I can update.
function res = mergeStructs(x,y)
if isstruct(x) && isstruct(y)
res = x;
names = fieldnames(y);
for fnum = 1:numel(names)
if isfield(x,names{fnum})
res.(names{fnum}) = mergeStructs(x.(names{fnum}),y.(names{fnum}));
else
res.(names{fnum}) = y.(names{fnum});
end
end
else
res = y;
end
Then res = mergeStructs(x,y); gives:
>> res.a
ans =
4
>> res.b
ans =
c: 2
d: 3
as you require.
EDIT: I added isstruct(x) && to the first line. The old version worked fine because isfield(x,n) returns 0 if ~isstruct(x), but the new version is slightly faster if y is a big struct and ~isstruct(x).