I want to edit this function==> diff(A(:,2​:end),1,2)​./diff(A(:​,1:end-1),​1,2), in order to create new q2,q3,q4..

I am sory i back again.

The answer yesterday very helpful.

http://www.mathworks.de/matlabcentral/answers/54646-how-to-produce-interval-from-this-matrix

but, it was only for 1 x-value. my x-value are from w1 until w9 or 10.

 this was my function and parameter:

.

k=[1,2,3,4,5,6,7]

.

x=2;

a=0.2 ;

w=(0:0.3:3)

S=cell2mat(arrayfun(@(k) 1-exp(-a*x*k.*w),k','un',0))

close

plot(w,S,'-+');

xlabel('w');

that function will produce column w1, w2, w3..w11 this:

ans =

Columns 1 through 6

         0    0.1131    0.2134    0.3023    0.3812    0.4512
         0    0.2134    0.3812    0.5132    0.6171    0.6988
         0    0.3023    0.5132    0.6604    0.7631    0.8347
         0    0.3812    0.6171    0.7631    0.8534    0.9093
         0    0.4512    0.6988    0.8347    0.9093    0.9502
         0    0.5132    0.7631    0.8847    0.9439    0.9727
         0    0.5683    0.8136    0.9195    0.9653    0.9850

Columns 7 through 11

    0.5132    0.5683    0.6171    0.6604    0.6988
    0.7631    0.8136    0.8534    0.8847    0.9093
    0.8847    0.9195    0.9439    0.9608    0.9727
    0.9439    0.9653    0.9785    0.9867    0.9918
    0.9727    0.9850    0.9918    0.9955    0.9975
    0.9867    0.9935    0.9968    0.9985    0.9993
    0.9935    0.9972    0.9988    0.9995    0.9998

and

by using the function below:

diff(A(:,2:end),1,2)./diff(A(:,1:end-1),1,2)

i will produce q value for only from first coulum as above, in my result as:

 Columns 1 through 6

    0.8869    0.8869    0.8869    0.8869    0.8869    0.8869
    0.7866    0.7866    0.7866    0.7866    0.7866    0.7866
    0.6977    0.6977    0.6977    0.6977    0.6977    0.6977
    0.6188    0.6188    0.6188    0.6188    0.6188    0.6188
    0.5488    0.5488    0.5488    0.5488    0.5488    0.5488
    0.4868    0.4868    0.4868    0.4868    0.4868    0.4868
    0.4317    0.4317    0.4317    0.4317    0.4317    0.4317

Columns 7 through 9

    0.8869    0.8869    0.8869
    0.7866    0.7866    0.7866
    0.6977    0.6977    0.6977
    0.6188    0.6188    0.6188
    0.5488    0.5488    0.5488
    0.4868    0.4868    0.4868
    0.4317    0.4317    0.4317

 this q  is only for one x-value (coulum first), in this case w1.

xlabel=w

ylabel=S

.

my goal is to produce next q2, q3...q9 or 10 from the columns w1, w2, w3, ..w9 .

maybe by editing the equation above:

diff(A(:,2:end),1,2)./diff(A(:,1:end-1),1,2)

which A refer to ans, or S.

i tried by my self like this

diff(A(:,2:end),2,3)./diff(A(:,1:end-1),2,3)

but the command state:

   Empty array: 7-by-0-by-0

[uncung fgv]

i close it by my self. i want to learn it before asking.