From 61e6457d14fa73274b6481871dddde98670600d1 Mon Sep 17 00:00:00 2001
From: Suryansh Dey <deysuryansh@gmail.com>
Date: Mon, 6 Apr 2026 17:16:13 +0530
Subject: [PATCH] feat: Creating a hyperSpec object without spectra

---
 NEWS.md        |  1 +
 R/initialize.R | 12 +++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/NEWS.md b/NEWS.md
index ce22ec5..9b58433 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -47,6 +47,7 @@
 ### Bugfixes
 
 * Possibility to initialize `hyperSpec` object by providing wavelengths only (cbeleites/hyperSpec#288).
+* Possibility to initialize `hyperSpec` object providing only `data` without `spc` (cbeleites/hyperSpec#296).
 * Column names in spectra matrix (`$spc` column of `hyperSpec` object) are now returned correctly by functions `spc.bin()` (cbeleites/hyperSpec#237), and `spc.loess()` (cbeleites/hyperSpec#245
 * `all.equal()` method for `hyperSpec` objects converted from S4 to S3 registration. The S4 `setMethod()` approach for this S3 generic caused roxygen2 (>= 7.3) to crash during documentation generation.
 * `rbind.fill()` (internal): strip the `AsIs` class from matrix columns after data frame assembly. R >= 4.4 introduced `all.equal.AsIs()` which caused spurious class-mismatch failures when comparing `hyperSpec` objects that had been through `rbind` or `collapse`.
diff --git a/R/initialize.R b/R/initialize.R
index 36b0521..a88bd51 100644
--- a/R/initialize.R
+++ b/R/initialize.R
@@ -96,6 +96,9 @@
 #'   spc = spc
 #' )
 #'
+#' # data only, no spectra
+#' new("hyperSpec", data = data.frame(x = 1:5))
+#'
 #' colnames(spc) <- 600:603
 #' new("hyperSpec", spc = spc) # wavelength taken from colnames (spc)
 #'
@@ -203,7 +206,8 @@ NULL
 
   # Deal with spectra
   if (is.null(spc) && is.null(data$spc)) {
-    spc <- structure(numeric(0), .Dim = c(0L, 0L))
+    nrows <- if (!is.null(data)) nrow(data) else 0L
+    spc <- structure(numeric(0), .Dim = c(nrows, 0L))
   }
 
   if (!is.null(spc) && !is.matrix(spc)) {
@@ -397,6 +401,12 @@ hySpc.testthat::test(.initialize) <- function() {
     expect_equal(hy_obj_1c, hy_obj_2c)
   })
 
+  test_that("data only, no spc", {
+    h <- new("hyperSpec", data = data.frame(c = 1:5))
+    expect_equal(dim(h), c(nrow = 5L, ncol = 2L, nwl = 0L))
+    expect_equal(h@wavelength, numeric(0))
+    expect_equal(h$c, 1:5)
+  })
 
   test_that('hyperSpec() and new("hyperSpec") give identical results', {
     expect_equal(hyperSpec(), new("hyperSpec"))