MaplePrimes - answers and comments on Question, plot an array

plot an array

gkokovidis — Wed, 17 Mar 2010 05:14:09 Z

Here is an example, that does not require loading any packages. There are other ways to do this, including pointplot, and scatterplot. ydata is your "array" of points. In your case it will have 25 elements.

restart:

ydata:=[4.019,3.986,3.883,3.640,3.344,3.113,2.940,2.731,2.464,2.202,2.016,1.843];

xdata:=[seq(i,i=0..nops(ydata))];

pair:=(x,y)->[x,y]:

P:=zip(pair,xdata,ydata):

plot(P);

Regards,
Georgios Kokovidis

Dräger Medical

it wouldnt plot anything.

CAJOS — Thu, 18 Mar 2010 20:48:39 Z

it wouldnt plot anything. The code for the array is

A := Array(1 .. 25);
for t from 1 to 25

do A[t] := f(t)

end do;

I need to plot the values from this array, A1 to A25 against t

(basically im trying to plot a decay graph)

zip

gkokovidis — Thu, 18 Mar 2010 21:54:55 Z

Here is yet another option to add to what Robert posted above this:

>restart:
>A := [`$`([t,exp(-t/5)], t = 1 .. 25)];
>plot(A);

Regards,
Georgios Kokovidis

Dräger Medical

with the second solution, i

CAJOS — Thu, 18 Mar 2010 22:02:56 Z

with the second solution, i get:

Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct

with the last solution i get:

Error, (in plots/tolist) points are not in the correct format

I have been told that turning the array into a list of 25 values and then plotting them is the way to do it. I thought there was a more simpilar way to turn the array into a plotable graph

gkokovidis I have a graph

CAJOS — Thu, 18 Mar 2010 22:27:22 Z

gkokovidis I have a graph now but doesnt use the array set up earlyer. Not that I am fussed, just it says to use the array to plot the graph.

Thanks anyways

zip

Robert Israel — Thu, 18 Mar 2010 21:45:23 Z

Georgios's code doesn't work because zip needs its two arguments to be of the same type. It would work if xdata was also an Array. Thus:

> xdata:= Array([$1..25]);

But a simpler one-line solution (assuming your f returns numeric values) is

> plot([seq]([i,f(i)],i=1..25), style=point);

or if you really need to use the Array A:

> plots[listplot](A, style=point);