# simplying of the statements

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Hege on 30 Jul 2020
Commented: Hege on 30 Jul 2020
I have attached two parts(part 1 and part 2) from my script and there are few parts like this and I want to simplify these hard coded statements. For easyness, I have attached two different statements only in here which means I just want understand my weakness once somebody guided me. All these i,j,k values are in 1:10 range. just expecting two different simplified statements for part(1) and part(2).
if ((j==1)&&(k==1)||(j==2)&&(k==2)||(j==3)&&(k==3)||(j==4)&&(k==4)||(j==5)&&(k==5)||(j==6)&&(k==6)||(j==7)&&(k==7)||(j==8)&&(k==8)||(j==9)&&(k==9)||(j==10)&&(k==10))&&((i==1)||(i==10));
B(i,j,k)=1;
else B(i,j,k)=0;%----------part (1)
if ((i==10)&&(j==1)||(i==9)&&(j==2)||(i==8)&&(j==3)||(i==7)&&(j==4)||(i==6)&&(j==5)||(i==5)&&(j==6)||(i==4)&&(j==7)||(i==3)&&(j==8)||(i==2)&&(j==9)||(i==1)&&(j==10))&&((k==1)||(k==10));
B(i,j,k)=1;
else B(i, j,k)=0;%----------part(2)

Sriram Tadavarty on 30 Jul 2020
Hi Yasasween,
Two things to make a simplied equation:
1. Assigning B with zeros, as all the dimensions are known at the first place. Implies, one can get away with else condition (i.e. B = zeros(10,10,10)
2. Now, placing the if conditions for the value of 1
% First condition
((j==1)&&(k==1)||(j==2)&&(k==2)||(j==3)&&(k==3)||(j==4)&&(k==4)||(j==5)&&(k==5)||(j==6)&&(k==6)||(j==7)&&(k==7)||(j==8)&&(k==8)||(j==9)&&(k==9)||(j==10)&&(k==10))&&((i==1)||(i==10));
% As can be seen in the above condition, the first part has j and k are equal, and then it is valid for i equals 1 or 10
% So, this can be the update or simplied statement for it
((j == k)) && (any(i == [1 10]))
% Second condition
((i==10)&&(j==1)||(i==9)&&(j==2)||(i==8)&&(j==3)||(i==7)&&(j==4)||(i==6)&&(j==5)||(i==5)&&(j==6)||(i==4)&&(j==7)||(i==3)&&(j==8)||(i==2)&&(j==9)||(i==1)&&(j==10))&&((k==1)||(k==10))
% As can be seen in the above condition, other than the last condiiton, all other conditions lead to a value of 11 when added
((i+j == 11)) || (any(k == [1 10]))
% In a similar fashion, based on the pattern of the conditions, the simplications can be made
Hope this helps.
Regards,
Sriram
Hege on 30 Jul 2020
Hi Sriram, Thank you so much for th explanation. This is working for my script.Thank you.

Walter Roberson on 30 Jul 2020
B(i,j,k) = ismember(i,[1 10]) && ismember(j, 1:10) && j == k; %part 1
B(i,j,k) = ismember(k,[1 10]) && ismember(j, 1:10) && i+j == 11; %part 2
Depending on the permitted range of j values, there would be some cases where these could be simplified to
B(i,j,k) = ismember(i,[1 10]) && j == k; %part 1
B(i,j,k) = ismember(k,[1 10]) && i+j == 11; %part 2
Hege on 30 Jul 2020
Hi Walter. Thank you so much for the explanation. This works very well. Thank you.

R2017a

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