I need help adding previous values to a vector

Hello, I am having trouble with a for loop. I have one vector and an initial value and I am trying to build a vector of new values from the original initial value. I provided a long-winded example of below and I am hoping to trim it down to something easier.

%dn=-0.05;
%radius=4:0.05:6;
%velocity=10;
%innerrad=4;
%outerrad=6;
%density=1000;
%P3=40;

%deltaP=(-dn*density*9.81/1/1000)-(density*(velocity^2)./radius./1./1000)*(dn);
%Pressurebefore=P3+101.3;

Pressure1=Pressurebefore+deltaP(1);
Pressure2=Pressure1+deltaP(2);
Pressure3=Pressure2+deltaP(3);
Pressure4=Pressure3+deltaP(4);
Pressure5=Pressure4+deltaP(5);
Pressure6=Pressure5+deltaP(6);

Answer 1

[madhan ravi]

dn=-0.05;
radius=4:0.05:6;
velocity=10;
innerrad=4;
outerrad=6;
density=1000;
P3=40;

deltaP=(-dn*density*9.81/1/1000)-(density*(velocity^2)./radius./1./1000)*(dn);
Pressurebefore=P3+101.3;
Pressure = zeros(1,numel(deltaP));
Pressure(1)=Pressurebefore+deltaP(1);

for k = 2:numel(deltaP)
    Pressure(k) = Pressure(k-1) +deltaP(k);
end

[Walter Roberson]

Pressure = Pressurebefore + cumsum(deltaP)

[madhan ravi]

xD , didn’t strike at that moment ;)