Finding the index of each last field of an array that contains a value between two set values

I have a 'kp' as one of the last fields of a structure (which is an array consisting of the same number, repeated) and have been using the following

kpindx=1;

kpdta = [];

for kpval = 1 : length(s)

    x =s(kpval).L.kp<=20;

    if sum(x) == length(s(kpval).L.kp)
        kpdta(kpindx) = kpval;
        kpindx = kpindx +1;
    end
end

s being my structure and kpdta being the output I want - an array containing the index numbers of s where kp<=20. I have been using this to give me the indices of which values of 'kp' are less than or equal to 20. Similarly, I have used it to give me the indices of each instance of s which contains a kp > 60. I want to adapt this to give me the indices of every instance of s that gives me the indices of every instance of s where 'kp' is greater than 20 but less than or equal to 20. I tried changing line 4 to

x =s(kpval).L.kp<=20 && s(kpval).HL.kp<=60

and unsurprisingly, this didn't work. If anyone could point me in the right direction, I'd be really greatful

Answer 1

[David Young]

It may be that you just need to use & instead of &&.

[Gareth Pritchard]

I feel a bit stupid for not trying this! Thanks a lot, it worked