Unrecognized function or variable 'x'.
显示 更早的评论
function y = Tsin(x,n)
x=input('Degrees: ');
y=input('Terms: ');
%Tsin calculates the sin using Taylor formula.
%Input arguments:
%x The angle in degrees, n number of terms.
z=x*pi/180;
y=0;
for k=0:n-1
y=y+(-1)^k*z^(2*k+1)/factorial(2*k+1);
end
RUN then
>> Tsin(x, n)
Unrecognized function or variable 'x'.
10 个评论
Tommy
2020-4-13
When you run
>> Tsin(x,n)
you need to provide values for both x and n. However, it looks like you are obtaining x within the function via this line:
x=input('Degrees: ');
If so, you do not need to supply x to your function. I would recommend changing the function definition to match
function y = Tsin(n)
and then calling
>> Tsin(n)
for whatever n value you want.
Emre Can Usengul
2020-4-13
Adam Danz
2020-4-13
There are lots of ways to ask users for input.
etc...
Nandini
2022-6-22
编辑：Walter Roberson
2024-10-20
PenaltyFactor=100;
LMUpdateRate=0.0100;
AbsoluteTolerance=5.0000e-06;
RelativeTolerance=0.0050;
MaxIterations=1000;
InitialIMFs=zeros(length(x),5);
InitialLM=zeros(length(x)+1,1);
CentralFrequencies= [];
InitializeMethod='peaks';
FFTLength=2*length(x);
NumIMFs= 5;
SignalLength= length(x);
HalfSignalLength=length(x)/2;
MirroredSignalLength=2*length(x);
DataType= 'double';
NumHalfFreqSamples= length(x)+1;
Display= 0;
%%
nfft = FFTLength;
penaltyFactor = PenaltyFactor;
numIMFs = NumIMFs;
relativeDiff = inf;
absoluteDiff = relativeDiff;
tau = LMUpdateRate; % Lagrange multiplier update rate
xr = [x(HalfSignalLength:-1:1); x; x(SignalLength:-1:ceil(SignalLength/2)+1)];
y = fft(xr,FFTLength);
sigFDFull = y;
% Get half of the bandwidth
sigFD = sigFDFull(1:NumHalfFreqSamples);
initIMFfdFull = fft(InitialIMFs,nfft);
initIMFfd = initIMFfdFull(1:NumHalfFreqSamples,:) + eps;
IMFfd = initIMFfd;
sumIMF = sum(IMFfd,2);
LM = InitialLM(:); % Lagrange Multiplier
%% Frequency vector from [0,0.5) for odd nfft and [0,0.5] for even nfft
f = (0:(nfft/2))/nfft;
%% Get the initial central frequencies
x=abs(sigFD);
BW = 2/FFTLength; % bandwidth of signal
minBWGapIndex = 2*BW/f(2);
x(x<mean(x)) = mean(x);
TF = islocalmax(x,'MinSeparation',minBWGapIndex);
pkst = x(TF);
locst = f(TF);
numpPeaks = length(pkst);
% Check for DC component
if x(1) >= x(2)
pks = zeros(numpPeaks+1,1);
locs = pks;
pks(2:length(pkst)+1) = pkst;
locs(2:length(pkst)+1) = locst;
pks(1) = x(1);
locs(1) = f(1);
else
pks = zeros(numpPeaks,1);
locs = pks;
pks(1:length(pkst)) = pkst;
locs(1:length(pkst)) = locst;
end
[~,index] = sort(pks,'descend');
centralFreq = 0.5*rand(NumIMFs,1);
% Check if the number of peaks is less than number of IMFs
if length(locs) < NumIMFs
centralFreq(1:length(locs(index))) = locs;
else
centralFreq(1:NumIMFs) = locs(index(1:NumIMFs));
end
%%
iter = 0;
f=f';
initIMFNorm = abs(initIMFfd).^2;
normIMF = zeros(size(initIMFfd,1),size(initIMFfd,2));
while (iter < MaxIterations && (relativeDiff > RelativeTolerance ||...
absoluteDiff > AbsoluteTolerance))
for kk = 1:numIMFs
sumIMF = sumIMF - IMFfd(:,kk);
IMFfd(:,kk) = (sigFD - sumIMF + LM/2)./...
(1+penaltyFactor*(f - centralFreq(kk)).^2);
normIMF(:,kk) = abs(IMFfd(:,kk)).^2;
centralFreq(kk) = (f.'*normIMF(:,kk))/sum(normIMF(:,kk));
sumIMF = sumIMF + IMFfd(:,kk);
end
LM = LM + tau*(sigFD-sumIMF);
absDiff = mean(abs(IMFfd-initIMFfd).^2);
absoluteDiff = sum(absDiff);
relativeDiff = sum(absDiff./mean(initIMFNorm));
% Sort IMF and central frequecies in descend order
% In ADMM, the IMF with greater power will be substracted first
[~,sortedIndex] = sort(sum(abs(IMFfd).^2),'descend');
IMFfd = IMFfd(:,sortedIndex);
centralFreq = centralFreq(sortedIndex(1:length(centralFreq)));
initIMFfd = IMFfd;
initIMFNorm = normIMF;
iter = iter + 1;
end
%%--------------------- Step 08 --------------------------------
%% Convert to time domain signal
% Transform to time domain
IMFfdFull = complex(zeros(nfft,numIMFs));
IMFfdFull(1:size(IMFfd,1),:) = IMFfd;
if ~mod(FFTLength,2)
IMFfdFull(size(IMFfd,1)+1:end,:) = conj(IMFfd(end-1:-1:2,:));
else
IMFfdFull(size(IMFfd,1)+1:end,:) = conj(IMFfd(end:-1:2,:));
end
[~,index] = sort(centralFreq,'descend');
%%
z=IMFfdFull(:,index);
xr = real(ifft(z,FFTLength));
IMFs_without_inbuild = xr(HalfSignalLength+1:MirroredSignalLength-HalfSignalLength,:);
residual_without_inbuild = PPGblr1 - sum(IMFs_without_inbuild,2);
Adam Danz
2022-6-24
@Patrick's answer moved here as a comment
-----------------------------------------------------------------
function Simpson1 (f1,a,b,M)
%F es el integrando como una cadena de caracteres
f=inline(f1);
h=(b-a)/(2*M);
s1=0;
s2=0;
for k=1:M
x=a+h*(2*k-1);
s1=s1+feval(f,x);
end
for k=1:M-1
x=a+h*2*k;
s2=s2+feval(f,x);
end
s=(h/3)*(feval(f,a)+feval(f,b)+4*s1+2*s2);
syms x
sv=int (f(x),a,b);
error=eval(abs(s-sv)*/abs(sv))*100;
disp('rpta simpson error true%')
fprintf('/t%0.5f/t%0.5f/n',s,error);
end
Console
Simpson1((9.8*67/12.5)*(1-exp(-12.5*x/67)),0,8,10)
Unrecognized function or variable 'x'.
@Patrick The error message tells you which variable is causing the problem: "x".
When you call the function using
Simpson1((9.8*67/12.5)*(1-exp(-12.5*x/67)),0,8,10)
% ^
the variable x is not defined.
Juan David
2024-4-6
移动：Voss
2024-4-6
% Función para calcular el valor de Lagrange
function y = lagrange2(X, Y)
n=length(X);
sym x;
for i=1:n
w=1;
for j=1:n
if j~=1
w = w * (x - X(j)) / (X(i) - X(j));
end
end
end
y = 0;
for i=1:n
y = y + w(i) * Y(i);
end
y=simplify(expand(ecuacion));
end
RUN then
Unrecognized function or variable 'x'.
Error in lagrange2 (line 10)
w = w * (x - X(j)) / (X(i) - X(j));
Voss
2024-4-6
Instead of
sym x;
use
syms x;
or
x = sym('x');
采纳的回答
You need to define the input variables. You cannot simply run a function that has undefined input variables.
x = 45
n = 8
Tsin(x,n)
____________________________________
Copy of question:
function y = Tsin(x,n)
x=input('Degrees: ');
y=input('Terms: ');
%Tsin calculates the sin using Taylor formula.
%Input arguments:
%x The angle in degrees, n number of terms.
z=x*pi/180;
y=0;
for k=0:n-1
y=y+(-1)^k*z^(2*k+1)/factorial(2*k+1);
end
RUN then
>> Tsin(x, n)
Unrecognized function or variable 'x'.
2 个评论
Dylan Radey
2021-3-3
can't define a variable for fiding a root :\
Adam Danz
2021-7-29
@Dylan Radey I don't know what that means. All variables are defined either directly by the user or from computations within the function/script.
更多回答（3 个）
Yuyang Mao
2021-8-5
1 个投票
I got the same problem before.
Explaination: Please make sure that you have add your function to the path!
solution:
- Click run, it jumps out a window
- click 'add to path', is shows error in red color which is fine
- now give the name of your function again, in your case is 'Tsin(x,n)'
And this should work.
Best,
Yuyang
2 个评论
Adam Danz
2021-8-9
Good advice. However, in this question, the function name is Tsin but the unrecognized variable name is x.
Jordan Wood
2021-8-10
Need to reinput the values you want for x and n in the command window
syms x
solve('x+3=4',x)
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