http://mathforum.org/kb/message.jspa?messageID=685890

i find equation above

for ii from 0 by 5 to 365 do
eq1 := x^2 + y^2 = arccos(x/r);
eq2 := y = evalf((atan(-1) - ii*Pi/180)/Pi)*(-1.0)*x;
xy := fsolve({eq1, eq2});
print("M",rhs(xy[1]),rhs(xy[2]),","):
od:

but i do not understand how to set r

i use a line scanning 365 degrees to get the path of swirl 

would like to get path data for c# WPF animation

but this method may have multiple solution because an intersection of swirl 

and a line can have multiple points

how to change rotation angle into slope of line?

with(MTM):
evalf(solve(atan(-1) - 45*Pi/180 = atan(x), x))*180/Pi;

above can not be solved

if angle is 30 degree

is following correct?

with(MTM):
angle := 30:
evalf((atan(-1) - 30*Pi/180)/Pi)*(-1.0);

how to use Riemann matrix to output Riemann surface?

and plot this surface?

with(algcurves):
f:=y^3+2*x^7-x^3*y;
pm:=periodmatrix(f,x,y);
evalf(pm, 5);
rm:=evalf(periodmatrix(f,x,y,Riemann),10);
M := rm;
A := proc (x, y) options operator, arrow; RiemannTheta([x, y], M, [], 0.1e-1, output = list)[2] end proc;
plot3d(Re(A(x+I*y, 0)), x = 0 .. 1, y = 0 .. 4, grid = [40, 40]);

is this graph Riemann Surface?

if so, how to convert A into polynomials?

updated:

i use 5 points trapezoid got RootOf  in result,

only 4 points is acceptable

when i try 5 points, there is no problem, but when more points such as

30 points, got RootOf for c sharp code

moreover, i got a problem when i copy the area1 result into 

visual studio c# code, it has error Integral Constant is too large

i find area2 has

m that i guess is genus,

but if i do not know genus number, how can i calculate with genus function

genus(y^m-(x...., x, y);

when i change m only the genus number is also changing

is my function wrong?

can i use this as a verification?

if m i set is 3 and then genus(...) result is 3

if result is equal to input 3, then it is correct function?