how do i find the distance between points

if i have x=[1,5,11,26,46,56,66,76,81];

and I want to find the distance between all these points. eg

1,5 = 4

5,11= 6

46,56=10

and if distances are the same add it to a counter

eg

46,56,66

distance = 10

counter = 3

[Rik]

What have you tried so far? It sounds like you can use diff to calculate the distance, and you might use it again to check for the number of repetitions.

Also, what exactly should your output look like?

[Jerry Li]

so i've tried using diff(x)

x=[1,5,11,26,46,56,66,76,81];
xdist=diff(x)
xdist =

       4     6    15    20    10    10    10     5

but I'm not sure how to add the interverals of distance 10 together

so i want an output something like

counter = 3 % 3 intervals of distance 10
if counter ==3;
function 1 % run fuction 1 as counter is equal to 3

Answer 1

[Image Analyst]

If you have the Statistics and Machine Learning Toolbox, you can get the distance of any element from any other element using pdist():

x = [1,5,11,26,46,56,66,76,81]';
distances1D = pdist(x);
distances = squareform(distances1D)

You get:

distances =
     0     4    10    25    45    55    65    75    80
     4     0     6    21    41    51    61    71    76
    10     6     0    15    35    45    55    65    70
    25    21    15     0    20    30    40    50    55
    45    41    35    20     0    10    20    30    35
    55    51    45    30    10     0    10    20    25
    65    61    55    40    20    10     0    10    15
    75    71    65    50    30    20    10     0     5
    80    76    70    55    35    25    15     5     0

For example to get the distance of the second element (5) to the fourth element (26) look in the second row, fourth column and you'll see it's 21, which is abs(26-5).