diff options
Diffstat (limited to 'ext/wasm/sql/000-mandelbrot.sql')
-rw-r--r-- | ext/wasm/sql/000-mandelbrot.sql | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/ext/wasm/sql/000-mandelbrot.sql b/ext/wasm/sql/000-mandelbrot.sql new file mode 100644 index 0000000..3aa5f57 --- /dev/null +++ b/ext/wasm/sql/000-mandelbrot.sql @@ -0,0 +1,17 @@ +WITH RECURSIVE + xaxis(x) AS (VALUES(-2.0) UNION ALL SELECT x+0.05 FROM xaxis WHERE x<1.2), + yaxis(y) AS (VALUES(-1.0) UNION ALL SELECT y+0.1 FROM yaxis WHERE y<1.0), + m(iter, cx, cy, x, y) AS ( + SELECT 0, x, y, 0.0, 0.0 FROM xaxis, yaxis + UNION ALL + SELECT iter+1, cx, cy, x*x-y*y + cx, 2.0*x*y + cy FROM m + WHERE (x*x + y*y) < 4.0 AND iter<28 + ), + m2(iter, cx, cy) AS ( + SELECT max(iter), cx, cy FROM m GROUP BY cx, cy + ), + a(t) AS ( + SELECT group_concat( substr(' .+*#', 1+min(iter/7,4), 1), '') + FROM m2 GROUP BY cy + ) +SELECT group_concat(rtrim(t),x'0a') as Mandelbrot FROM a; |