How to write multiple if statements

Can i write more than 3 if statements?

if i can why did i get this error?!

   ??? elseif source1(i,j)==3;
    |
Error: Illegal use of reserved keyword "elseif".

this happens after i use

    if source1(i,j)==1;

and

    elseif source1(i,j)==2;

plus i want to use if condition for seven times!

[Kevin Claytor]

Can you post more of the code, there may be a line before the elseif that is causing the error.

[Jan]

Arman has posted the code and accepted it by accident. I've deleted this answer and moved the code to the comment section, because it is not useful to explain the actual problem.

source1=csvread('C:\Users\Arman\Desktop\Matlab\CSVread\1st source_grid_csv.csv');
site=[60.5,31.5];
Mmin=4;
DM=0.1;
c1=-1.09;
c2=0.238;
c3=-1;
c4=-0.0005;
sigma=0.15;
sumNy=zeros(1,1.5/0.01);
CellArea=0.01*112.2*0.01*96.3;
for i=1:521
for j=1:400
if source(i,j)~=-9999;
Celldecimal=[(57.935+(j-1)*0.01),(34.108-(i-1)*0.01)];
R= acos(sin(site(1,2)*pi/180)*sin(Celldecimal(1,2)*pi/180)+cos(site(1,2)*pi/180)*cos(Celldecimal(1,2)*pi/180)*cos((Celldecimal(1,1)-site(1,1))*pi/180))*6371;
if source1(i,j)==1;
a=-1.6739;
b=0.6531;
Mmax=7.8;
Davg=17;
beta=b*log(10);
NM0=10^(a)*CellArea;
NMmin=NM0*(exp(-beta*Mmin)-exp(-beta*Mmax))/(1-exp(-beta*Mmax));
r=sqrt(R^(2)+Davg^(2));
for PGA=0.01:0.01:1.5
Nymatrix=zeros((7.9-Mmin+DM)/DM,1);
for aa=Mmin:0.1:Mmax
Mmean=aa+0.05;
Freq=NMmin*(exp(-beta*(aa-Mmin))-exp(-beta*((aa+0.1)-Mmin)))/(1-exp(-beta*(Mmax-Mmin)));
loga=log10(PGA);
logamean=c1+c2*Mmean+c3*log10(r)+c4*r;
lognormal=1-normcdf(loga,logamean,sigma);
Ny=Freq*lognormal;
if aa==Mmin
Nymatrix((aa-Mmin+DM)/DM,1)=Ny;
else
Nymatrix(round((aa-Mmin+DM)/DM),1)=Ny+Nymatrix(round((aa-Mmin)/DM),1);
end
end
sumNy(1,round(PGA/0.01))=sum(Nymatrix,1)+sumNy(1,round(PGA/0.01));
end
end
elseif source1(i,j)==2;
a=-0.2525;
b=1.1351;
Mmax=5.7;
Davg=16;
beta=b*log(10);
beta=b*log(10);
NM0=10^(a)*CellArea;
NMmin=NM0*(exp(-beta*Mmin)-exp(-beta*Mmax))/(1-exp(-beta*Mmax));
r=sqrt(R^(2)+Davg^(2));
for PGA=0.01:0.01:1.5
Nymatrix=zeros((7.9-Mmin+DM)/DM,1);
for aa=Mmin:0.1:Mmax
Mmean=aa+0.05;
Freq=NMmin*(exp(-beta*(aa-Mmin))-exp(-beta*((aa+0.1)-Mmin)))/(1-exp(-beta*(Mmax-Mmin)));
loga=log10(PGA);
logamean=c1+c2*Mmean+c3*log10(r)+c4*r;
lognormal=1-normcdf(loga,logamean,sigma);
Ny=Freq*lognormal;
if aa==Mmin
Nymatrix((aa-Mmin+DM)/DM,1)=Ny;
else
Nymatrix(round((aa-Mmin+DM)/DM),1)=Ny+Nymatrix(round((aa-Mmin)/DM),1);
end
end
sumNy(1,round(PGA/0.01))=sum(Nymatrix,1)+sumNy(1,round(PGA/0.01));
end
end
elseif source1(i,j)==3;
a=-1.2474;
b=0.8548;
Mmax=6.3;
Davg=20;
beta=b*log(10);
NM0=10^(a)*CellArea;
NMmin=NM0*(exp(-beta*Mmin)-exp(-beta*Mmax))/(1-exp(-beta*Mmax));
r=sqrt(R^(2)+Davg^(2));
for PGA=0.01:0.01:1.5
Nymatrix=zeros((7.9-Mmin+DM)/DM,1);
for aa=Mmin:0.1:Mmax
Mmean=aa+0.05;
Freq=NMmin*(exp(-beta*(aa-Mmin))-exp(-beta*((aa+0.1)-Mmin)))/(1-exp(-beta*(Mmax-Mmin)));
loga=log10(PGA);
logamean=c1+c2*Mmean+c3*log10(r)+c4*r;
lognormal=1-normcdf(loga,logamean,sigma);
Ny=Freq*lognormal;
if aa==Mmin
Nymatrix((aa-Mmin+DM)/DM,1)=Ny;
else
Nymatrix(round((aa-Mmin+DM)/DM),1)=Ny+Nymatrix(round((aa-Mmin)/DM),1);
end
end
sumNy(1,round(PGA/0.01))=sum(Nymatrix,1)+sumNy(1,round(PGA/0.01));
end
end
elseif source1(i,j)==4;
a=-1.1237;
b=0.8127;
Mmax=7.1;
Davg=18;
beta=b*log(10);
NM0=10^(a)*CellArea;
NMmin=NM0*(exp(-beta*Mmin)-exp(-beta*Mmax))/(1-exp(-beta*Mmax));
r=sqrt(R^(2)+Davg^(2));
for PGA=0.01:0.01:1.5
Nymatrix=zeros((7.9-Mmin+DM)/DM,1);
for aa=Mmin:0.1:Mmax
Mmean=aa+0.05;
Freq=NMmin*(exp(-beta*(aa-Mmin))-exp(-beta*((aa+0.1)-Mmin)))/(1-exp(-beta*(Mmax-Mmin)));
loga=log10(PGA);
logamean=c1+c2*Mmean+c3*log10(r)+c4*r;
lognormal=1-normcdf(loga,logamean,sigma);
Ny=Freq*lognormal;
if aa==Mmin
Nymatrix((aa-Mmin+DM)/DM,1)=Ny;
else
Nymatrix(round((aa-Mmin+DM)/DM),1)=Ny+Nymatrix(round((aa-Mmin)/DM),1);
end
end
sumNy(1,round(PGA/0.01))=sum(Nymatrix,1)+sumNy(1,round(PGA/0.01));
end
end
elseif source1(i,j)==5;
a=-1.4385;
b=0.7444;
Mmax=7;
Davg=19;
beta=b*log(10);
NM0=10^(a)*CellArea;
NMmin=NM0*(exp(-beta*Mmin)-exp(-beta*Mmax))/(1-exp(-beta*Mmax));
r=sqrt(R^(2)+Davg^(2));
for PGA=0.01:0.01:1.5
Nymatrix=zeros((7.9-Mmin+DM)/DM,1);
for aa=Mmin:0.1:Mmax
Mmean=aa+0.05;
Freq=NMmin*(exp(-beta*(aa-Mmin))-exp(-beta*((aa+0.1)-Mmin)))/(1-exp(-beta*(Mmax-Mmin)));
loga=log10(PGA);
logamean=c1+c2*Mmean+c3*log10(r)+c4*r;
lognormal=1-normcdf(loga,logamean,sigma);
Ny=Freq*lognormal;
if aa==Mmin
Nymatrix((aa-Mmin+DM)/DM,1)=Ny;
else
Nymatrix(round((aa-Mmin+DM)/DM),1)=Ny+Nymatrix(round((aa-Mmin)/DM),1);
end
end
sumNy(1,round(PGA/0.01))=sum(Nymatrix,1)+sumNy(1,round(PGA/0.01));
end
end
elseif source1(i,j)==6;
a=-1.6544;
b=0.6865;
Mmax=7.8;
Davg=23;
beta=b*log(10);
NM0=10^(a)*CellArea;
NMmin=NM0*(exp(-beta*Mmin)-exp(-beta*Mmax))/(1-exp(-beta*Mmax));
r=sqrt(R^(2)+Davg^(2));
for PGA=0.01:0.01:1.5
Nymatrix=zeros((7.9-Mmin+DM)/DM,1);
for aa=Mmin:0.1:Mmax
Mmean=aa+0.05;
Freq=NMmin*(exp(-beta*(aa-Mmin))-exp(-beta*((aa+0.1)-Mmin)))/(1-exp(-beta*(Mmax-Mmin)));
loga=log10(PGA);
logamean=c1+c2*Mmean+c3*log10(r)+c4*r;
lognormal=1-normcdf(loga,logamean,sigma);
Ny=Freq*lognormal;
if aa==Mmin
Nymatrix((aa-Mmin+DM)/DM,1)=Ny;
else
Nymatrix(round((aa-Mmin+DM)/DM),1)=Ny+Nymatrix(round((aa-Mmin)/DM),1);
end
end
sumNy(1,round(PGA/0.01))=sum(Nymatrix,1)+sumNy(1,round(PGA/0.01));
end
end
elseif source1(i,j)==7;
a=-0.9803;
b=0.8746;
Mmax=6.2;
Davg=22;
beta=b*log(10);
NM0=10^(a)*CellArea;
NMmin=NM0*(exp(-beta*Mmin)-exp(-beta*Mmax))/(1-exp(-beta*Mmax));
r=sqrt(R^(2)+Davg^(2));
for PGA=0.01:0.01:1.5
Nymatrix=zeros((7.9-Mmin+DM)/DM,1);
for aa=Mmin:0.1:Mmax
Mmean=aa+0.05;
Freq=NMmin*(exp(-beta*(aa-Mmin))-exp(-beta*((aa+0.1)-Mmin)))/(1-exp(-beta*(Mmax-Mmin)));
loga=log10(PGA);
logamean=c1+c2*Mmean+c3*log10(r)+c4*r;
lognormal=1-normcdf(loga,logamean,sigma);
Ny=Freq*lognormal;
if aa==Mmin
Nymatrix((aa-Mmin+DM)/DM,1)=Ny;
else
Nymatrix(round((aa-Mmin+DM)/DM),1)=Ny+Nymatrix(round((aa-Mmin)/DM),1);
end
end
sumNy(1,round(PGA/0.01))=sum(Nymatrix,1)+sumNy(1,round(PGA/0.01));
end
end
end
end
end
Y=0.01:0.01:1.5;
loglog(sumNy,Y);
axis([.0001 .01 .01 1.5])

Answer 1

[C.J. Harris]

You have too many 'end' statements within your code. An if-else statement should be formatted like this:

if a == 1
   % Code
elseif a == 2
   % Code
elseif a == 3
   % Code
else 
   % Code
end

In your code however you appear to have put an 'end' before each 'elseif' statement which is resulting in the error you are seeing.

[Arman Kam]

thank you my dear friend, i wanna make your answer the accepted but there was a mistake. thanks

[Jan]

I've accepted this answer for you.

Answer 2

[Leah]

looks like you have an end before all your elseif's that shouldn't be there. It helps to smart indent your code when doing nested if's. Press Ctrl+A (select all) then Ctrl+I (smart indent). The structure of your code seems to be

if source(i,j)==2
   % bunch of code
else if source(i,j)==3
          % bunch of code
    else if source(i,j)=4
            % bunch of code
        end
    end
end

Notice all of the end go at the bottom. To clean this up you might want to use a switch case statement. which would look like this

switch source(i,j)
   case 2
       % bunch of code
   case 3
       % bunch of code
   case 4
      % bunch of code
case 9999
        % bunch of code
case otherwise
        % bunch of code
end

Answer 3

[Goh XinYee]

nono, it is that there is a difference between

else if

and

elseif

...

it is not correct to type else if, as with every 'if', we need an 'end', which is why the program won't run with only one 'end'.

    if
        else if
            else if
            
            end
        end
    end

however, it is not that case with 'elseif', there is only one 'if' with many 'elseif' (s), and thus only one 'end' is needed.

    if
        elseif
        
        elseif
    end