# Create a loop with decrementing step

2 views (last 30 days)
Dennis M on 25 Aug 2021
Commented: Dennis M on 2 Sep 2021
Good Day, May I ask a question, how can I create loop that the output is like this (10 20 29 38 47 56 65 and so on) and (80 70 61 53 46 40 35 and so on) same in negative (-10 -20 -29 -38 -47 -56 -65 and so on) and (-80 -70 -61 -53 -46 -40 -35 and so on)
Thanks

the cyclist on 25 Aug 2021
Do you mean that you want the increment to be 10, 9, 8, ...? (That is not what your first example does). Here is one way to do a series like that. I hope you can generalize to what you need.
inc = 10:-1:1;
step = cumsum(inc)
step = 1×11
10 19 27 34 40 45 49 52 54 55 55
Dennis M on 2 Sep 2021
Good Day,
Sir The Cyclist,
Here's my script please check if there's improvement, thanks
clear all
format compact
finalstep = 0.125;
%%
starta = 20;
stopa = 30;
hysa = abs(stopa - starta);
stastep = hysa * 0.2;
stepa = linspace(finalstep,stastep,hysa);
A = stopa - cumsum([0 stepa]);
A = A(A >= starta);
intermediatesa = flipud(A.').';
for loop_variablea = intermediatesa
%body of the loop goes here
a = loop_variablea
end
%%
startb = 15;
stopb = 5;
hysb = abs(stopb - startb);
stastep = hysb * 0.2;
stepb = linspace(finalstep,stastep,hysb);
B = stopb + cumsum([0 stepb]);
B = B( B <= startb);
intermediatesb = flipud(B.').';
for loop_variableb = intermediatesb
%body of the loop goes here
b = loop_variableb
end
%%
startx = -20;
stopx = -30;
hysx = abs(stopx - startx);
stastep = hysx * 0.2;
stepx = linspace(finalstep,stastep,hysx);
X = stopx + cumsum([0 stepx]);
X = X(X <= startx);
intermediatesx = flipud(X.').';
for loop_variablex = intermediatesx
%body of the loop goes here
x = loop_variablex
end
%%
starty = -15;
stopy = -5;
hysy = abs(stopy - starty);
stastep = hysy * 0.2; % start step
stepy = linspace(finalstep,stastep,hysy);
Y = stopy - cumsum([0 stepy]);
Y = Y(Y >= starty);
intermediatesy = flipud(Y.').';
for loop_variabley = intermediatesy
%body of the loop goes here
y = loop_variabley
end