Mercurial > hg > svcore
changeset 1459:3a128665fa6f horizontal-scale
Fixes to logarithmic scale tick intervals. The approach here is not right, though -- and I've left in a failing test or two to remind me of that
| author | Chris Cannam |
|---|---|
| date | Wed, 02 May 2018 14:17:10 +0100 |
| parents | 0fb5d4e6edeb |
| children | 9528c73aa98c |
| files | base/ScaleTickIntervals.h base/test/TestScaleTickIntervals.h |
| diffstat | 2 files changed, 167 insertions(+), 12 deletions(-) [+] |
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--- a/base/ScaleTickIntervals.h Tue Apr 24 15:02:54 2018 +0100 +++ b/base/ScaleTickIntervals.h Wed May 02 14:17:10 2018 +0100 @@ -182,6 +182,11 @@ { Display display = Auto; +#ifdef DEBUG_SCALE_TICK_INTERVALS + SVDEBUG << "ScaleTickIntervals::logInstruction: Range is " + << r.min << " to " << r.max << endl; +#endif + if (r.n < 1) { return {}; } @@ -196,33 +201,71 @@ double digInc = log10(inc); int precInc = int(floor(digInc)); + double roundTo = pow(10.0, precInc); +#ifdef DEBUG_SCALE_TICK_INTERVALS + SVDEBUG << "ScaleTickIntervals::logInstruction: Naive increment is " + << inc << ", of " << digInc << "-digit length" << endl; + SVDEBUG << "ScaleTickIntervals::logInstruction: " + << "So increment is precision " << precInc + << ", yielding rounding for increment of " + << roundTo << endl; +#endif + if (roundTo != 0.0) { inc = round(inc / roundTo) * roundTo; if (inc < roundTo) inc = roundTo; + +#ifdef DEBUG_SCALE_TICK_INTERVALS + SVDEBUG << "ScaleTickIntervals::logInstruction: " + << "Rounded increment to " << inc << endl; +#endif } // if inc is close to giving us powers of two, nudge it if (fabs(inc - 0.301) < 0.01) { inc = log10(2.0); + +#ifdef DEBUG_SCALE_TICK_INTERVALS + SVDEBUG << "ScaleTickIntervals::logInstruction: " + << "Nudged increment to " << inc << " to get powers of two" + << endl; +#endif } // smallest increment as displayed double minDispInc = LogRange::unmap(r.min + inc) - LogRange::unmap(r.min); +#ifdef DEBUG_SCALE_TICK_INTERVALS + SVDEBUG << "ScaleTickIntervals::logInstruction: " + << "Smallest displayed increment is " << minDispInc << endl; +#endif + int prec = 1; if (minDispInc > 0.0) { - prec = int(floor(log10(minDispInc))); + prec = int(ceil(log10(minDispInc))) - 1; + if (prec == 0) prec = 1; if (prec < 0) prec = -prec; + +#ifdef DEBUG_SCALE_TICK_INTERVALS + SVDEBUG << "ScaleTickIntervals::logInstruction: " + << "Precision therefrom is " << prec << endl; +#endif } if (r.max >= -2.0 && r.max <= 3.0 && r.min >= -3.0 && r.min <= 3.0) { display = Fixed; if (prec == 0) prec = 1; + +#ifdef DEBUG_SCALE_TICK_INTERVALS + SVDEBUG << "ScaleTickIntervals::logInstruction: " + << "Min and max within modest range, adjusted precision to " + << prec << " and display to Fixed" << endl; +#endif } #ifdef DEBUG_SCALE_TICK_INTERVALS @@ -259,16 +302,58 @@ } static Tick makeTick(Display display, int precision, double value) { + if (value == -0.0) { value = 0.0; } + const int buflen = 40; char buffer[buflen]; - snprintf(buffer, buflen, - display == Auto ? "%.*g" : - display == Fixed ? "%.*f" : - "%.*e", - precision, value); + + if (display == Auto) { + + int digits = (value != 0.0 ? int(ceil(log10(abs(value)))) : 0); + + // This is not the same logic as %g uses for determining + // whether to delegate to use scientific or fixed notation + + if (digits < -3 || digits > 4) { + + display = Auto; // delegate planning to %g + + } else { + + display = Fixed; + + // in %.*f, the * indicates decimal places, not sig figs + if (precision > digits) { + precision -= digits; + } else if (precision == digits) { + precision = 1; + } else if (precision + 1 < digits) { + double r = pow(10, digits - precision - 1); + value = r * round(value / r); + precision = 0; + } else { + precision = 0; + } + } + } + + const char *spec = (display == Auto ? "%.*g" : + display == Scientific ? "%.*e" : + "%.*f"); + +#pragma GCC diagnostic ignored "-Wformat-nonliteral" + + snprintf(buffer, buflen, spec, precision, value); + +#ifdef DEBUG_SCALE_TICK_INTERVALS + SVDEBUG << "makeTick: spec = \"" << spec + << "\", prec = " << precision << ", value = " << value + << ", label = \"" << buffer << "\"" << endl; +#endif + return Tick({ value, std::string(buffer) }); }
--- a/base/test/TestScaleTickIntervals.h Tue Apr 24 15:02:54 2018 +0100 +++ b/base/test/TestScaleTickIntervals.h Wed May 02 14:17:10 2018 +0100 @@ -428,7 +428,7 @@ // pathological range auto ticks = ScaleTickIntervals::linear({ 1, 1, 10 }); ScaleTickIntervals::Ticks expected { - { 1.0, "1" } + { 1.0, "1.0" } }; compareTicks(ticks, expected); } @@ -438,7 +438,7 @@ // pathological range auto ticks = ScaleTickIntervals::linear({ 0, 0, 10 }); ScaleTickIntervals::Ticks expected { - { 0.0, "0" } + { 0.0, "0.0" } }; compareTicks(ticks, expected); } @@ -458,7 +458,7 @@ // senseless input auto ticks = ScaleTickIntervals::linear({ 0, 1, 0 }); ScaleTickIntervals::Ticks expected { - { 0.0, "0" }, + { 0.0, "0.0" }, }; compareTicks(ticks, expected); } @@ -468,7 +468,7 @@ // senseless input auto ticks = ScaleTickIntervals::linear({ 0, 1, -1 }); ScaleTickIntervals::Ticks expected { - { 0.0, "0" }, + { 0.0, "0.0" }, }; compareTicks(ticks, expected); } @@ -518,7 +518,7 @@ { auto ticks = ScaleTickIntervals::logarithmic({ M_PI, 6.022140857e23, 7 }); ScaleTickIntervals::Ticks expected { - { 1000, "1e+03" }, + { 1000, "1000.0" }, { 1e+06, "1e+06" }, { 1e+09, "1e+09" }, { 1e+12, "1e+12" }, @@ -528,7 +528,7 @@ }; compareTicks(ticks, expected, true); } - + void log_0p465_778_10() { auto ticks = ScaleTickIntervals::logarithmic({ 0.465, 778.08, 10 }); @@ -548,6 +548,76 @@ compareTicks(ticks, expected); } + void log_1_10k_10() + { + auto ticks = ScaleTickIntervals::logarithmic({ 1.0, 10000.0, 10 }); + ScaleTickIntervals::Ticks expected { + { 1.0, "1.0" }, + { 2.5, "2.5" }, + { 6.0, "6.0" }, + { 16.0, "16.0" }, + { 40.0, "40.0" }, + { 100.0, "100.0" }, + { 250.0, "250.0" }, + { 600.0, "600.0" }, + { 1600.0, "1600.0" }, + { 4000.0, "4000.0" }, + { 10000.0, "1e+04" }, + }; + compareTicks(ticks, expected, true); + } + + void log_80_10k_6() + { + auto ticks = ScaleTickIntervals::logarithmic({ 80.0, 10000.0, 6 }); + ScaleTickIntervals::Ticks expected { + { 130, "130" }, + { 260, "260" }, + { 510, "510" }, + { 1000, "1000" }, + { 2000, "2000" }, + { 4100, "4100" }, + { 8200, "8200" } + }; + compareTicks(ticks, expected, true); + } + + void log_80_800k_10() + { + auto ticks = ScaleTickIntervals::logarithmic({ 80.0, 800000.0, 10 }); + ScaleTickIntervals::Ticks expected { + { 100, "100" }, + { 251, "251" }, + { 631, "631" }, + { 1580, "1580" }, + { 3980, "3980" }, + { 10000, "10000" }, + { 25100, "2.5e+04" }, + { 63100, "6.3e+04" }, + { 160000, "1.6e+05" }, + { 400000, "4e+05" }, + }; + compareTicks(ticks, expected, true); + } + + void log_0_1_0() + { + // senseless input + auto ticks = ScaleTickIntervals::logarithmic({ 0, 1, 0 }); + ScaleTickIntervals::Ticks expected { + }; + compareTicks(ticks, expected); + } + + void log_0_1_m1() + { + // senseless input + auto ticks = ScaleTickIntervals::logarithmic({ 0, 1, -1 }); + ScaleTickIntervals::Ticks expected { + }; + compareTicks(ticks, expected); + } + }; #endif