// SumFunc implements Func and sums the values of all argument
// traces into a single trace.
//
// MISSING_DATA_SENTINEL values are not included in the sum. Note that if all
// the values at an index are MISSING_DATA_SENTINEL then the sum will be
// MISSING_DATA_SENTINEL.
func (SumFunc) Eval(ctx *Context, node *Node) ([]*types.PerfTrace, error) {
if len(node.Args) != 1 {
return nil, fmt.Errorf("Sum() takes a single argument.")
}
if node.Args[0].Typ != NodeFunc {
return nil, fmt.Errorf("Sum() takes a function argument.")
}
traces, err := node.Args[0].Eval(ctx)
if err != nil {
return nil, fmt.Errorf("Sum() argument failed to evaluate: %s", err)
}
if len(traces) == 0 {
return traces, nil
}
ret := types.NewPerfTraceN(len(traces[0].Values))
ret.Params()["id"] = tiling.AsFormulaID(ctx.formula)
for i, _ := range ret.Values {
sum := 0.0
count := 0
for _, tr := range traces {
if v := tr.Values[i]; v != config.MISSING_DATA_SENTINEL {
sum += v
count += 1
}
}
if count > 0 {
ret.Values[i] = sum
}
}
return []*types.PerfTrace{ret}, nil
}
// addCalculatedTraces adds the traces returned from evaluating the given
// formula over the given tile to the QueryResponse.
func addCalculatedTraces(qr *QueryResponse, tile *tiling.Tile, formula string) error {
ctx := parser.NewContext(tile)
traces, err := ctx.Eval(formula)
if err != nil {
return fmt.Errorf("Failed to evaluate formula %q: %s", formula, err)
}
hasFormula := false
for _, tr := range traces {
if tiling.IsFormulaID(tr.Params()["id"]) {
hasFormula = true
}
tg := traceGuiFromTrace(tr, tr.Params()["id"], tile)
qr.Traces = append(qr.Traces, tg)
}
if !hasFormula {
// If we haven't added the formula trace to the response yet, add it in now.
f := types.NewPerfTraceN(len(tile.Commits))
tg := traceGuiFromTrace(f, tiling.AsFormulaID(formula), tile)
qr.Traces = append(qr.Traces, tg)
}
return nil
}
// geoFunc implements Func and merges the values of all argument
// traces into a single trace with a geometric mean.
//
// MISSING_DATA_SENTINEL and negative values are not included in the mean.
// Note that if all the values at an index are MISSING_DATA_SENTINEL or
// negative then the mean will be MISSING_DATA_SENTINEL.
func (GeoFunc) Eval(ctx *Context, node *Node) ([]*types.PerfTrace, error) {
if len(node.Args) != 1 {
return nil, fmt.Errorf("geo() takes a single argument.")
}
if node.Args[0].Typ != NodeFunc {
return nil, fmt.Errorf("geo() takes a function argument.")
}
traces, err := node.Args[0].Eval(ctx)
if err != nil {
return nil, fmt.Errorf("geo() argument failed to evaluate: %s", err)
}
if len(traces) == 0 {
return traces, nil
}
ret := types.NewPerfTraceN(len(traces[0].Values))
ret.Params()["id"] = tiling.AsFormulaID(ctx.formula)
for i, _ := range ret.Values {
// We're accumulating a product, but in log-space to avoid large N overflow.
sumLog := 0.0
count := 0
for _, tr := range traces {
if v := tr.Values[i]; v >= 0 && v != config.MISSING_DATA_SENTINEL {
sumLog += math.Log(v)
count += 1
}
}
if count > 0 {
// The geometric mean is the N-th root of the product of N terms.
// In log-space, the root becomes a division, then we translate back to normal space.
ret.Values[i] = math.Exp(sumLog / float64(count))
}
}
return []*types.PerfTrace{ret}, nil
}