How to plot Projectile Motion?

I'm trying to create a function which is able to solely interpret the initial vertical and horizontal velocities of an object, then fully plot this motion. Here's what I have:

%User is prompted to input the initial velocities.
YVel = input('input initial vertical velocity ');
XVel = input('input initial horizontal velocity ');

%User is prompted for choice of planet in order to determine acceleration
%due to gravity
PlanetChoice = input('Where is this taking place? 1. Earth 2. Mars ');
if PlanetChoice == 1
  YAccel = -9.8;
elseif PlanetChoice == 2
  YAccel = -3.8;
end

%We assume that the object lands on the same height as the origin for this 
%projection.
MaxHt = SCalc(0,YVel,YAccel);
TimeUp = TCalc(0,YVel,YAccel);
TimeDown = TCalc(-YVel,0,Accel);
TimeTot = TimeUp+TimeDown;

%Vectors are created for the vertical and horizontal displacement.
YVec = zeros(1, ceil(TimeTot/0.1));
XVec = zeros(1, ceil(TimeTot/0.1));

%Uses index values in order to loop and fill vectors.
TimeIndex = 0;
VecIndex = 1;

for TimeIndex <= ceil(TimeTot/0.1)
  YVec(VecIndex) = SYFinal(YVel,Accel,TimeIndex);
  XVec(VecIndex) = SXFinal(XVel,TimeIndex);
  TimeIndex = TimeIndex + 0.1;
  VecIndex = VecIndex + 1;
end

plot(XVec,YVec)

The error that I'm having return to me, refers to the for loop. " invalid left hand side of assignment

plot(XVec,YVec)cIndex + 1;0.1;l,TimeIndex);ndex);ht as the origin for this"

Not sure how to fix this. Please excuse the length and ridiculous amount going on, as I'm expected to write this much for this piece of work.

Answer 1

[Walter Roberson]

for is used to indicate repetition where the iteration values are known ahead of time, such as

for k=1:10 
for word=[7, 2, 11]

When you want to repeat as long as a condition is satisfied then you need to use while