`plot_pattern()` produces an error if only 1 pattern is requested

[Hanne Oberman]

There should be a check on the npat argument. I think the minimum number of patterns should be 2?

ggmice::plot_pattern(mice::nhanes, square = FALSE, rotate = TRUE, cluster = "age", npat = 1)
#> Error in apply(pat[-nrow(pat), ord], 1, function(x) paste(as.numeric(x), : dim(X) must have a positive length

^{Created on 2023-01-25 with reprex v2.0.2}

[Hanne Oberman]

E.g. use is.vector() and as.matrix() to modify the md pattern object into a matrix with nrow=1 instead of a vector

[Hanne Oberman]

Look into drop = FALSE as alternative

[Hanne Oberman]

@hanneoberman Note to self: check message npat

10 missing data patterns were requested and 11 missing data patterns are shown. 94 missing data patterns are hidden.

when 10 patterns are shown

[Hanne Oberman]

The current solution (throwing an error) is not ideal. See e.g. #103

ggmice::plot_pattern(mice::nhanes, square = FALSE, rotate = TRUE, cluster = "age", npat = 1)
#> Error in ggmice::plot_pattern(mice::nhanes, square = FALSE, rotate = TRUE, : The minimum number of patterns to display is two. Please provide an integer greater than one.

^{Created on 2023-06-27 with reprex v2.0.2}

[Hanne Oberman]

@pepijnvink could you please revert the error message solution and fix the incorrect number of patterns in the warning message?

[Hanne Oberman]

@pepijnvink unfortunately, this should also be done for the complete data, because md.pattern does provide a plot.

mice::md.pattern(na.omit(mice::nhanes))
#>  /\     /\
#> {  `---'  }
#> {  O   O  }
#> ==>  V <==  No need for mice. This data set is completely observed.
#>  \  \|/  /
#>   `-----'

#>    age bmi hyp chl  
#> 13   1   1   1   1 0
#>      0   0   0   0 0

^{Created on 2023-06-27 with reprex v2.0.2}