How do I delete the weird flat line?

How do I delete the flat green line that appears? It seems to just pop in for no reason.

Current= xlsread(path,sheet,['B2:B' num2str(unique+1)]);
PeakPower= xlsread(path,sheet,['E2:E' num2str(unique+1)]);
Slope=PeakPower/Current;
figure(SlopevsA) 
plot(Current,Slope)    
hold on

That is my code

Answer 1

[Adam Danz]

If your variables Current and PeakPower are column vectors (which appears to be the case), when you divide them

Slope=PeakPower/Current;

the output, Slope is a matrix and at least one column of that matrix are zeros which produces the straight line at y=0.

[Walter Roberson]

Perhaps the instruction should be

 Slope = PeakPower ./ Current;