Save spending time and output it

[LittleBeannie]

We will save the spending time of a design and output it to a designated location. This issue will be addressed immediately after the completion of issue #523.

[LittleBeannie]

Four areas where spending time output may appear:

• direct output, i.e., a list of design, enroll_rate, fail_rate, bound, and analysis.
• gt summary table
• gt bound summary table
• textural summary

> gs_design_ahr(info_frac = 1:3/3)

$design
# [1] "ahr"
 
$enroll_rate
# A tibble: 3 × 3
  stratum duration  rate
  <chr>      <dbl> <dbl>
1 All            2  14.2
2 All            2  28.5
3 All           10  42.7

$fail_rate
# A tibble: 2 × 5
  stratum duration fail_rate dropout_rate    hr
  <chr>      <dbl>     <dbl>        <dbl> <dbl>
1 All            3    0.0770        0.001   0.9
2 All          100    0.0385        0.001   0.6

$bound
# A tibble: 6 × 7
  analysis bound probability probability0      z `~hr at bound` `nominal p`
     <int> <chr>       <dbl>        <dbl>  <dbl>          <dbl>       <dbl>
1        1 upper     0.00484     0.000104  3.71           0.485    0.000104
2        1 lower     0.00459     0.0641   -1.52           1.35     0.936   
3        2 upper     0.402       0.00605   2.51           0.707    0.00601 
4        2 lower     0.0437      0.704     0.534          0.929    0.297   
5        3 upper     0.900       0.0247    1.99           0.799    0.0231  
6        3 lower     0.100       0.975     1.99           0.799    0.0233  

$analysis
# A tibble: 3 × 10
  analysis  time     n event   ahr theta  info info0 info_frac info_frac0
     <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>     <dbl>      <dbl>
1        1  12.5  450.  105. 0.806 0.216  25.8  26.2     0.334      0.333
2        2  21.3  513.  210. 0.729 0.316  51.3  52.4     0.664      0.667
3        3  36    513.  315. 0.683 0.381  77.3  78.7     1          1    

attr(,"class")
[1] "non_binding" "ahr"         "gs_design"   "list"       
attr(,"uninteger_is_from")
[1] "gs_design_ahr"

> gs_design_ahr(info_frac = 1:3/3) %>% text_summary()
[1] "Asymmetric two-sided group sequential design with non-binding futility bound, 3 analyses, time-to-event outcome with sample size 513 and 314.6 events, 90 percent power, 2.5 percent (1-sided) Type I error to detect hazard ratio of 0.9 during the first 3 months and 0.6 thereafter. Enrollment and total study durations are assumed to be 14 and 36 months, respectively. Efficacy bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters). Futility bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters)."