How to draw concentric arcs in a 120 degree sector and the contour plots for mass flux of water spray in each concentric compartment ?

%% for polar plot

theta = linspace(0,120,8); % angle division

rho = [0.000959931, 0.051254502, 0.025132741, 0.099483767, 0.174300215, 0.134972129, 0.0429351, 0.015068009]; % mass flux values

polarplot(theta,rho)

%% to plot concentric arcs

n = 120;

r = 0:0.01:0.75;

r=r';

theta = pi*(0:(n))/180;

Y = r*cos(theta);

X = r*sin(theta);

plot(X,Y)

%% contour plots for mass flux density

x1 = 0.05:.10:0.75; % radius (in m) at which concentric arcs are drawn for 120 ° sector

x2 = linspace(0,120,8); % angle division

[X1, X2]= meshgrid(x1,x2);

z = [0.000959931, 0.051254502, 0.025132741, 0.099483767, 0.174300215, 0.134972129, 0.0429351, 0.015068009]; % mass flux values

figure

contourf (x1, x2, z)

Answer 1

[Chunru]

%% for polar plot 
theta = linspace(0,120,8);    % angle division
rho = [0.000959931, 0.051254502, 0.025132741, 0.099483767, 0.174300215, 0.134972129, 0.0429351, 0.015068009];  % mass flux values
polarplot(deg2rad(theta),rho)       % use radian for theta

%% to plot concentric arcs  
% (change the order of theta and r)
n = 120;
r = 0:0.01:0.75;
theta = deg2rad(0:n);
X = cos(theta') * r;
Y = sin(theta') * r;
plot(X,Y); axis equal

%% contour plots for mass flux density 
% z = [0.000959931, 0.051254502, 0.025132741, 0.099483767, 0.174300215, 0.134972129, 0.0429351, 0.015068009];  % mass flux values
% z should be compatible with x1 and x2, e.g.
Z = sqrt(X.^2 + Y.^2);

figure 
contourf (X, Y, Z); axis equal

%% For data r and z
r = [0.05, 0.15,0.25,0.35,0.45,0.55,0.65,0.75];          %sector radius
z1 =  [0.000959931, 0.051254502, 0.025132741, 0.099483767, 0.174300215, 0.134972129, 0.0429351, 0.015068009]; 
X = cos(theta') * r;
Y = sin(theta') * r;
Z = repmat(z1, [length(theta), 1]);

figure 
contourf (X, Y, Z, 5); axis equal

Answer 2

[raghav sikka]

Thanks for reply ! I forgot to convert in radian..

I am afraid the rho vector (mass flux values) is defined based on radius 'r' not theta as like in polar plot such that first value 0.000959931) corresponds to (first) inner most concentric sector of radius 0.05 m and so on...

rho = [0.000959931, 0.051254502, 0.025132741, 0.099483767, 0.174300215, 0.134972129, 0.0429351, 0.015068009]; % mass flux values

The first (inner) concentric sector is 0.05 m in radius, then 0.10 m difference until radius r = 0.75 m.

[Chunru]

I could not guess what is your desired data. Do you have an equation for the output Z?

[raghav sikka]

I dont have any equation of z as it is related to radius r only (not angle, that is to plot concentric arcs 120 ° sector )

The values of rho vector is the z vector for 8 concentric sectors.

r = [0.05, 0.15,0.25,0.35,0.45,0.55,0.65,0.75] %sector radius

z (rho) = [0.000959931, 0.051254502, 0.025132741, 0.099483767, 0.174300215, 0.134972129, 0.0429351, 0.015068009]; % mass flux values

[Chunru]

See the update above.

[raghav sikka]

yes, it is showing many lines , how to make it smooth?

could we also plot contours using meshgrid and surfc function ?

[Chunru]

You can control the number of levels in contour as shown above.

However, if you really want to have smooth display. You need to have smoother data.

[raghav sikka]

Thank you.

yes, I agree it needs more data to make it smoother.

But we have 8 levels only. can we plot only 8 levels in contour? also, why there is a gap at center region (white) ?

How to replicate it for other two sectors to make it a full concentric circle (360 deg)?

[Chunru]

If you do want to use exactly 8 levels for the similar data you have provided, you can consider to use "patch". doc patch for more info.

The center region white gap is due to no data along that part (rho does not start from 0)

For full concentric plot, you need to make theta 360 deg. For three sectors, you can hold on and plot other two sectors on same plot.

Answer 3

[raghav sikka]

r = [0.05, 0.15:0.1:0.75]; % gives 8 sectors

rho = [0.000959931, 0.051254502, 0.025132741, 0.099483767, 0.174300215, 0.134972129, 0.0429351, 0.015068009]; % mass flux values .... why still gap at the center?

How to use patch(x,y) for each concentric sector (r=0.05,0.15:0.1:0.75); ?