Convert duration with full precision

[terrorfisch]

This pull request fixes a duration value change (#475 ) when converting it from float to TimeType(arbitrary precision via fractions) by abusing float to str to get a consistent rounding.

This might lead to unexpected consequences due to float rounding errors with fractional times.

TODO:

• Add more test cases
• Quantify performance impact

I think the factor 2 worse performance (with gmpy) is worth the improved ergonomics.

@eendebakpt

[terrorfisch]

Best solution I came up with is to abuse str to get a consistent rounding that doesn't throw of the user.

[terrorfisch]

typo

[terrorfisch]

Benchmarks indicate a 10% performance hit in "combined" benchmark. For raw computations there is a factor of 2 overhead over gmpy2.

The new code needs ~10µs per numeric operation and ~20µs to convert a float (on my machine).

[terrorfisch]

Before:

Name (time in ms)                                     Min                Max              Mean            StdDev            Median               IQR            Outliers       OPS            Rounds  Iterations
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
test_time_type_addition_with_float_performance     2.1304 (1.0)       2.4029 (1.0)      2.1588 (1.0)      0.0390 (1.0)      2.1450 (1.0)      0.0113 (1.0)         47;67  463.2255 (1.0)         468           1
test_time_type_from_float_performance              5.4950 (2.58)     32.0087 (13.32)    5.7039 (2.64)     2.0004 (51.34)    5.5399 (2.58)     0.0336 (2.97)         1;19  175.3199 (0.38)        175           1
test_time_type_mul_performance                     5.8042 (2.72)      6.1170 (2.55)     5.8695 (2.72)     0.0553 (1.42)     5.8441 (2.72)     0.0899 (7.96)         45;2  170.3719 (0.37)        171           1
test_time_type_addition_performance                5.9069 (2.77)      6.2421 (2.60)     5.9923 (2.78)     0.0579 (1.49)     5.9740 (2.79)     0.0773 (6.84)         51;3  166.8818 (0.36)        167           1
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

After:

Name (time in ms)                                      Min                Max               Mean            StdDev             Median               IQR            Outliers      OPS            Rounds  Iterations
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
test_time_type_mul_performance                     11.2950 (1.0)      11.6003 (1.0)      11.3918 (1.0)      0.0682 (1.0)      11.3823 (1.0)      0.0997 (1.0)          22;1  87.7828 (1.0)          88           1
test_time_type_addition_performance                11.5525 (1.02)     12.6481 (1.09)     12.0731 (1.06)     0.2080 (3.05)     12.0662 (1.06)     0.2563 (2.57)         20;2  82.8286 (0.94)         82           1
test_time_type_from_float_performance              20.3693 (1.80)     47.5711 (4.10)     21.3644 (1.88)     3.8722 (56.78)    20.7756 (1.83)     0.3648 (3.66)          1;2  46.8069 (0.53)         48           1
test_time_type_addition_with_float_performance     32.0184 (2.83)     40.9395 (3.53)     32.9890 (2.90)     1.7793 (26.09)    32.4464 (2.85)     0.4329 (4.34)          3;5  30.3131 (0.35)         27           1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

[coveralls]

Pull Request Test Coverage Report for Build 1866

• 124 of 140 (88.57%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.03%) to 89.875%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
qupulse/expressions.py	2	3	66.67%
qupulse/utils/types.py	118	133	88.72%

Totals
Change from base Build 1856:	-0.03%
Covered Lines:	26055
Relevant Lines:	28610

---

💛 - Coveralls