## digitalmars.D.learn - polar coordinates with ggplotd

• brocolis (38/38) Sep 18 2016 I've tried this code.
• brocolis (2/40) Sep 18 2016 Found an error in ys line. Thanks.
brocolis <brocolis deb.null> writes:
```I've tried this code.

import ggplotd.ggplotd;
import ggplotd.geom;
import ggplotd.aes;
import ggplotd.axes;
import std.math;

auto r(double theta)
{
return 2 * sin(6*theta);
}

auto getX(double theta)
{
return r(theta) * cos(theta);
}

auto getY(double theta)
{
return r(theta) * sin(theta);
}

void main()
{
import std.array : array;
import std.algorithm : map;
import std.range : iota;

auto theta = iota(0, 2*PI, 0.1).array;
auto xs = theta.map!((x) => getX(x)).array;
auto ys = xs.map!((x) => getY(x)).array;

auto gg = GGPlotD().put( geomLine( Aes!(typeof(xs), "x",
typeof(ys), "y")(xs, ys) ) );

gg.put( xaxisRange(-5, 5) ).put( xaxisLabel( "x" ) );
gg.put( yaxisRange(-5, 5) ).put( yaxisLabel( "y" ) );
gg.put( xaxisOffset(0) ).put( yaxisOffset(0) );
gg.save( "output.png", 500, 300 );
}

And I got the output: http://imgur.com/KwLYJpN

Expected:
https://www.wolframalpha.com/input/?i=polar+plot+2*sin(6*theta)

I need to somehow activate "polar" mode in ggplotd. Thanks.
```
Sep 18 2016
brocolis <brocolis deb.null> writes:
```On Sunday, 18 September 2016 at 22:07:31 UTC, brocolis wrote:
I've tried this code.

import ggplotd.ggplotd;
import ggplotd.geom;
import ggplotd.aes;
import ggplotd.axes;
import std.math;

auto r(double theta)
{
return 2 * sin(6*theta);
}

auto getX(double theta)
{
return r(theta) * cos(theta);
}

auto getY(double theta)
{
return r(theta) * sin(theta);
}

void main()
{
import std.array : array;
import std.algorithm : map;
import std.range : iota;

auto theta = iota(0, 2*PI, 0.1).array;
auto xs = theta.map!((x) => getX(x)).array;
auto ys = xs.map!((x) => getY(x)).array;

auto gg = GGPlotD().put( geomLine( Aes!(typeof(xs), "x",
typeof(ys), "y")(xs, ys) ) );

gg.put( xaxisRange(-5, 5) ).put( xaxisLabel( "x" ) );
gg.put( yaxisRange(-5, 5) ).put( yaxisLabel( "y" ) );
gg.put( xaxisOffset(0) ).put( yaxisOffset(0) );
gg.save( "output.png", 500, 300 );
}

And I got the output: http://imgur.com/KwLYJpN

Expected:
https://www.wolframalpha.com/input/?i=polar+plot+2*sin(6*theta)

I need to somehow activate "polar" mode in ggplotd. Thanks.

Found an error in ys line. Thanks.
```
Sep 18 2016
Edwin van Leeuwen <edder tkwsping.nl> writes:
```On Sunday, 18 September 2016 at 22:13:35 UTC, brocolis wrote:
Found an error in ys line. Thanks.

Does that mean you solved it?

Currently there is no special support for other coordinate
systems, but I recently added Guides for x/y coordinates which
should make this relatively straightforward to implement and is
next on the list. Not sure when I'll get a chunk of time to
implement it though.

For now you will have to convert the coordinates yourself, before
plotting them.
```
Sep 19 2016
brocolis <brocolis deb.null> writes:
```On Monday, 19 September 2016 at 12:34:56 UTC, Edwin van Leeuwen
wrote:
On Sunday, 18 September 2016 at 22:13:35 UTC, brocolis wrote:
Found an error in ys line. Thanks.

Does that mean you solved it?

Currently there is no special support for other coordinate
systems, but I recently added Guides for x/y coordinates which
should make this relatively straightforward to implement and is
next on the list. Not sure when I'll get a chunk of time to
implement it though.

For now you will have to convert the coordinates yourself,
before plotting them.

Yeah, problem solved. Thanks.
```
Sep 19 2016