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static: Reduce stddev of initial solution

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Signed-off-by: gatecat <gatecat@ds0.me>
This commit is contained in:
gatecat 2023-11-26 15:54:16 +01:00 committed by myrtle
parent c13b34f20e
commit 6d9322457e
1 changed files with 3 additions and 5 deletions
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8
common/place/placer_static.cc
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@ -282,8 +282,8 @@ class StaticPlacer
float m = std::sqrt(-2.f * std::log(u1));
float z0 = m * std::cos(2.f * pi * u2);
float z1 = m * std::sin(2.f * pi * u2);
float x = (width / 2.f) + (width / 50.f) * z0;
float y = (height / 2.f) + (height / 50.f) * z1;
float x = (width / 2.f) + (width / 250.f) * z0;
float y = (height / 2.f) + (height / 250.f) * z1;
x = std::min<float>(width - 1.f, std::max<float>(x, 0));
y = std::min<float>(height - 1.f, std::max<float>(y, 0));
return RealPair(x, y);
@ -527,8 +527,6 @@ class StaticPlacer
for (int idx = 0; idx < int(ccells.size()); idx++) {
auto &mc = mcells.at(idx);
auto &g = groups.at(mc.group);
// scale width and height to be at least one bin (local density smoothing from the eplace paper)
// TODO: should we really do this every iteration?
auto loc = mc.pos;
auto size = mc.rect;
@ -923,7 +921,7 @@ class StaticPlacer
steplen = get_steplen();
log_info("iter=%d steplen=%f a=%f\n", iter, steplen, nesterov_a);
float a_next = (1.0f + std::sqrt(4.0f * nesterov_a * nesterov_a + 1)) / 2.0f;
// Update positions according to trivial gradient descent (let's leave Nesterov's for later...)
// Update positions using Nesterov's
for (auto &cell : mcells) {
if (cell.is_fixed || cell.is_dark)
continue;