1 files changed, 61 insertions, 0 deletions
diff --git a/tests/stdlib/tstats.nim b/tests/stdlib/tstats.nim
new file mode 100644
index 000000000..728d93d09
--- /dev/null
+++ b/tests/stdlib/tstats.nim
@@ -0,0 +1,61 @@
+discard """
+  matrix: "--mm:refc; --mm:orc"
+"""
+
+import std/[stats, assertions]
+import std/math
+
+
+func `~=`(x, y: float32): bool =
+  math.almostEqual(x, y)
+
+template main() =
+  var rs: RunningStat
+  rs.push(@[1.0, 2.0, 1.0, 4.0, 1.0, 4.0, 1.0, 2.0])
+  doAssert(rs.n == 8)
+  doAssert rs.mean ~= 2.0
+  doAssert rs.variance() ~= 1.5
+  doAssert rs.varianceS() ~= 1.71428571
+  doAssert rs.skewness() ~= 0.81649658
+  doAssert rs.skewnessS() ~= 1.01835015
+  doAssert rs.kurtosis() ~= -1.0
+  doAssert rs.kurtosisS() ~= -0.7000000000000001
+
+  var rs1, rs2: RunningStat
+  rs1.push(@[1.0, 2.0, 1.0, 4.0])
+  rs2.push(@[1.0, 4.0, 1.0, 2.0])
+  let rs3 = rs1 + rs2
+  doAssert rs3.variance ~= rs.variance
+  doAssert rs3.skewness ~= rs.skewness
+  doAssert rs3.kurtosis ~= rs.kurtosis
+  rs1 += rs2
+  doAssert rs1.variance ~= rs.variance
+  doAssert rs1.skewness ~= rs.skewness
+  doAssert rs1.kurtosis ~= rs.kurtosis
+  rs1.clear()
+  rs1.push(@[1.0, 2.2, 1.4, 4.9])
+  doAssert rs1.sum ~= 9.5
+  doAssert rs1.mean() ~= 2.375
+
+  when not defined(cpu32):
+    # XXX For some reason on 32bit CPUs these results differ
+    var rr: RunningRegress
+    rr.push(@[0.0, 1.0, 2.8, 3.0, 4.0], @[0.0, 1.0, 2.3, 3.0, 4.0])
+    doAssert rr.slope() ~= 0.9695585996955861
+    doAssert rr.intercept() ~= -0.03424657534246611
+    doAssert rr.correlation() ~= 0.9905100362239381
+    var rr1, rr2: RunningRegress
+    rr1.push(@[0.0, 1.0], @[0.0, 1.0])
+    rr2.push(@[2.8, 3.0, 4.0], @[2.3, 3.0, 4.0])
+    let rr3 = rr1 + rr2
+    doAssert rr3.correlation() ~= rr.correlation()
+    doAssert rr3.slope() ~= rr.slope()
+    doAssert rr3.intercept() ~= rr.intercept()
+
+  block: # bug #18718
+    var rs: RunningStat
+    rs.push(-1.0)
+    doAssert rs.max == -1.0
+
+static: main()
+main()