How can can this code be made more efficient?

% The intial heights, plus gravity and velocity

i_h = 0:0.25:95;
t_h = 0:0.25:105;
g_h = 0:0.25:115;
j_h = 0:0.25:125;
k_h = 0:0.25:135;
l_h = 0:0.25:145;
a_h = 0:0.25:155;
z_h = 0:0.25:165;
x_h = 0:0.25:175;
c_h = 0:0.25:185;
v_h = 0:0.25:195;
g = 9.81;
v = 85;

% Equations: d is distance and distance is relative to the inital height equation present 

d_0 = (v*sqrt(2*i_h/g));
d_1 = (v*sqrt(2*t_h/g));
d_2 = (v*sqrt(2*g_h/g));
d_3 = (v*sqrt(2*j_h/g));
d_4 = (v*sqrt(2*k_h/g));
d_5 = (v*sqrt(2*l_h/g));
d_6 = (v*sqrt(2*a_h/g));
d_7 = (v*sqrt(2*z_h/g));
d_8 = (v*sqrt(2*x_h/g));
d_9 = (v*sqrt(2*c_h/g));
d_10 = (v*sqrt(2*v_h/g));

%plot

figure;
plot(d_0, i_h(end)-i_h)
hold on
plot(d_1, t_h(end)-t_h)
hold on
plot(d_2, g_h(end)-g_h)
hold on
plot(d_3, j_h(end)-j_h)
hold on
plot(d_4, k_h(end)-k_h)
hold on
plot(d_5, l_h(end)-l_h)
hold on
plot(d_6, a_h(end)-a_h)
hold on
plot(d_7, z_h(end)-z_h)
hold on
plot(d_8, x_h(end)-x_h)
hold on
plot(d_9, c_h(end)-c_h)
hold on
plot(d_10, v_h(end)-v_h)
hold off
title 'i_h'
ylabel ('Height (m)')
xlabel ('Distance (m)')
legend('95 metres', '105 Metres', '115 Metres', '125 Metres', '135 Metres', '145 Metres', '155 Metres', '165 Metres', '175 Metres', '185 Metres', '195 Metres')
grid on

[Sam Chak]

Hi @Thomas,

Your new question is related to coding efficiency. By the way, has the plotting issue from your previous question been technically resolved? Link to the previous question.

Answer 1

[Dyuman Joshi]

Instead of dynamically naming variables, use a for loop.

%Constants
g = 9.81;
v = 85;

%Arrays of values to be used
vec = 95:10:195;

figure
hold on

for k=vec
    arr_k = 0:0.25:k;
    d_k = v*sqrt(2*arr_k/g);
    plot(d_k, arr_k(end)-arr_k)  
end

hold off
grid on
title('i_h')
ylabel('Height (m)')
xlabel('Distance (m)')

%Take advantage of the properties of strings to make the legend
legend(vec + " Metres")

Also, have a read here - TUTORIAL: Why Variables Should Not Be Named Dynamically (eval)

[Thomas]

Thank you