black

URL = https://github.com/ambv/black
This is estimation of issues occurence for black of user ambv.

Info:

Estimated at 16.1.2019 19:05:29.

Initial number of total defects = 670
Total defects in repository after processing and filtering = 74

Filters and Processors:

Filters:
- FilterByLabel used, with filtering words: [bug, error, fail, fault, defect]
- FilterClosed used to filter out opened issues.
Processors:
- None

Trend test:

Trend exists .
Trend = -11.273722598341902

Time between failures

Comparison of 5 models:

Goel-Okemura model

Model function:
μ(t) = a * (1 - e-b*t)
Estimated parameters:
a = 75.60405310698337
b = 0.1238510325488274
Estimated by Least Squares.

Goodness of fit:

Chi-Square = 7.331283141217985
Chi-Square significance level = 99.99999998275257%
Chi-Square null hypothesis rejection = ACCEPT

Goel-Okemura S-Shaped model

Model function:
μ(t) = a * (1 - (1 + b*t) * e-b*t)
Estimated parameters:
a = 73.2368406609132
b = 0.2745073531643493
Estimated by Least Squares.

Goodness of fit:

Chi-Square = 96.16793409488025
Chi-Square significance level = 6.091588517054269E-4%
Chi-Square null hypothesis rejection = REJECT

Hossain-Dahiya model

Model function:
μ(t) = a * (1 - e-b*t) / (1 + c*e-b*t)
Estimated parameters:
a = 75.41479238839901
b = 0.1300157868272037
c = 0.0796625074278388
Estimated by Least Squares.

Goodness of fit:

Chi-Square = 7.238239015538538
Chi-Square significance level = 99.99999998630332%
Chi-Square null hypothesis rejection = ACCEPT

Musa-Okumoto model

Model function:
μ(t) = α * ln(β * t + 1)
Estimated parameters:
α = 20.410106048701234
β = 1.168675633092294
Estimated by Least Squares.

Goodness of fit:

Chi-Square = 13.76329203324361
Chi-Square significance level = 99.99936921340755%
Chi-Square null hypothesis rejection = ACCEPT

Duane model

Model function:
μ(t) = α * tβ
Estimated parameters:
α = 24.052499025330153
β = 0.3253663366539554
Estimated by Least Squares.

Goodness of fit:

Chi-Square = 29.77402416906325
Chi-Square significance level = 93.72395974779566%
Chi-Square null hypothesis rejection = ACCEPT

Failure occurence