change warning about 'stack imbalance' to appear only once, after the…

… first call to a model fitting function if the data are filebacked

R/plmm_checks.R

@@ -84,7 +84,7 @@ plmm_checks <- function(design,
   # set default init
   if(is.null(init)){init <- rep(0, std_X_p)}
 
-    # set default gamma (gamma not used in 'lasso' option)
+  # set default gamma (gamma not used in 'lasso' option)
   if (missing(gamma)) gamma <- switch(penalty, SCAD = 3.7, MCP = 3, lasso = 1)
 
   # error checking design matrix  ---------------------------------------------
@@ -121,6 +121,23 @@ plmm_checks <- function(design,
     plink_flag <- FALSE
   }
 
+  # warn about bigalgebra issues if this is user's first call to filebacked analysis
+  # Check if the warning has been shown
+  if (!.plmmr_env$warning_shown & fbm_flag) {
+
+    warning("Note: plmmr depends on the package bigalgebra, the current GitHub \n
+            version of which is throwing some warnings for filebacked analysis. \n
+            See https://github.com/fbertran/bigalgebra/issues/2 \n
+            If you see a warning about 'stack imbalance' appear while you are \n
+            fitting a model with plmm() or cv_plmm(), we recommend downloading \n
+            the last stable version of bigalebra.\n
+            This message is displayed after your first call to fit a model \n
+            using filebacked data.\n")
+
+    # Update the state
+    .plmmr_env$warning_shown <- TRUE
+  }
+
   # return list for model preparation ---------------------------------
   ret <- list(
     std_X = std_X,

R/zzz.R

@@ -1,8 +1,9 @@
 .onAttach <- function(libname, pkgname) {
-  packageStartupMessage("This is version ", utils::packageVersion(pkgname),
-                        " of ", pkgname, ".\n",
-                        "Note: ", pkgname, " depends on the package bigalgebra, the current GitHub version of which is throwing some warnings for filebacked analysis.
-\n https://github.com/fbertran/bigalgebra/issues/2 \n
-If you see a warning about 'stack imbalance' appear while you are fitting a model with plmm() or cv_plmm(), we recommend downloading the last stable version of bigalebra.
-If you are analyzing data stored in your R session memory, you can disregard this message.")
-}
+  packageStartupMessage("This is ", pkgname, " ", utils::packageVersion(pkgname), ".\n")
+}
+
+# Define an environment to store the state
+.plmmr_env <- new.env()
+
+# Initialize the state
+.plmmr_env$warning_shown <- FALSE