Re: subplot and stem in matlab work but not work in octave of Discrete-time Signals

[Josu Jugo]

> Hi,

The funcion stem is not implemented in octave (At list, I don't known), but
the sentence:

subplot(2,1,1); stem(n1,x1); title('Sequence in Example 2.2a')

is quite equivalent to:

title('Sequence in Example 2.2a'); subplot(2,1,1); plot(n1,x1,'^')

(Observe the different order of title)

josu

> | Dear octave expert:
> |
> |    I copy some simple program from book "Digital Siganl Processing,
> | using Matlab V.4" author by Vinay K.Ingle John G. Proakis from PWS
> | published at page 15, example 2.2,
> |
> |    my octave2.0.14 complain subplot and stem not be defined by gnuplot
> | and stem.m file, so it also still can draw but not discrete graph
> rather
> | a connected(although not smooth, segmented) graph,
> |
> |    Do any one know how to justify it, or where is the source code, we
> | need to modify or adding new feature?
> |
> | at matlab input
> | >>n=-2:10; x=[1:7,6:-1:1];
> | >>[x11,n11]=sigshift(x,n,5); [x12,n12]=sigshift(x,n,-4);
> | >>[x1,n1]=sigadd(2*x11,n11,-3*x12,n12);
> | >>subplot(2,1,1); stem(n1,x1); title('Sequence in Example 2.2a')
> | >>xlabel('n'); ylabel('x1(n)');

> |
> |
> | it should execute:
> | x1(n) = 2x(n-5) -3x(n+4)
> |
> | where x(n)= {1,2,3,4,5,7,6,5,4,3,2,1}
> |
> |
> | Hope to get your(any octave expert) help (address@hidden)(Do octave
> have
> | any news group?)function [y,n] = sigadd(x1,n1,x2,n2)
> | n=min(min(n1),min(n2)): max(max(n1), max(n2));
> | y1=zeros(1,length(n)); y2=y1;
> | y1(find((n>=min(n1))&(n<=max(n1))==1))=x1;
> | y2(find((n>=min(n2))&(n<=max(n2))==1))=x2;
> | y=y1+y2;
> |
> | function [y,n] = sigshift(x,m,n0)
> | n=m+n0;  y=x;
> |
>
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