Cannot handle NULL shape constraint arguments

[johnnybonney]

The function breaks if shape constraint arguments are specified as NULL. Of course, it is easy to work around this by not specifying the argument at all, but my understanding is that it is pretty standard to allow for this kind of thing.

set.seed(1001)
N <- 2000

dt <- data.table(
  id = 1:N,
  u = runif(N),
  z = sample(1:4, N, replace = T),
  epsilon = rnorm(N, sd = .1)
)

dt[, p := (z == 1)*0.12 + (z == 2)*0.29 + (z == 3)*0.48 + (z == 4)*0.78]
dt[, d := as.integer(u <= p)]
dt[, y0 := 0.9 - 1.1*u + 0.3*u^2]
dt[, y1 := 0.35 - 0.3*u - 0.05*u^2]
dt[, y := y1*d + y0*(1 - d) + epsilon]

res <- ivmte(data = dt,
             propensity = d ~ factor(z),
             ivlike = c(y ~ d, y ~ factor(z)),
             target = "ate",
             lpsolver = "gurobi",
             m1 = ~u,
             m0 = ~u,
             m1.inc = NULL) # or m0.inc, m0.dec, m1.dec, mte.dec, mte.inc

LP solver: Gurobi ('gurobi')

Obtaining propensity scores...
Generating target moments...
    Integrating terms for control group...
    Integrating terms for treated group...
Generating IV-like moments...
    Moment 1...
    Moment 2...
    Moment 3...
    Moment 4...
    Moment 5...
    Moment 6...
Performing audit procedure...
    Generating audit grid...
 Error in if (try(m1.inc, silent = TRUE) == TRUE) { : 
  argument is of length zero 

[jkcshea]

Ah, this is something I had forgotten to check.

I've now incorporated a check to make sure that the monotonicity constraints are declared using only TRUE or FALSE (so NULL is not allowed), and that the shape constraints are declared using only numerical values.