Predicting MCIA global (factor) scores for new test samples

It may be of interest to use the embedding that is calculated on a training sample set to predict scores on a test set (or, equivalently, on new data).

After loading the nipalsMCIA library, we randomly split the NCI60 cancer cell line data into training and test sets.

Installation

# devel version

# install.packages("devtools")
devtools::install_github("Muunraker/nipalsMCIA", ref = "devel",
                         force = TRUE, build_vignettes = TRUE) # devel version
# release version
if (!require("BiocManager", quietly = TRUE))
  install.packages("BiocManager")

BiocManager::install("nipalsMCIA")
library(ggplot2)
library(MultiAssayExperiment)
library(nipalsMCIA)

Split the data

data(NCI60)
set.seed(8)

num_samples <- dim(data_blocks[[1]])[1]
num_train <- round(num_samples * 0.7, 0)
train_samples <- sample.int(num_samples, num_train)

data_blocks_train <- data_blocks
data_blocks_test <- data_blocks

for (i in seq_along(data_blocks)) {
  data_blocks_train[[i]] <- data_blocks_train[[i]][train_samples, ]
  data_blocks_test[[i]] <- data_blocks_test[[i]][-train_samples, ]
}

# Split corresponding metadata
metadata_train <- data.frame(metadata_NCI60[train_samples, ],
                             row.names = rownames(data_blocks_train$mrna))
colnames(metadata_train) <- c("cancerType")

metadata_test <- data.frame(metadata_NCI60[-train_samples, ],
                            row.names = rownames(data_blocks_test$mrna))
colnames(metadata_test) <- c("cancerType")

# Create train and test mae objects
data_blocks_train_mae <- simple_mae(data_blocks_train, row_format = "sample",
                                    colData = metadata_train)
data_blocks_test_mae <- simple_mae(data_blocks_test, row_format = "sample",
                                   colData = metadata_test)

Run nipalsMCIA on training data

MCIA_train <- nipals_multiblock(data_blocks = data_blocks_train_mae,
                                col_preproc_method = "colprofile", num_PCs = 10,
                                plots = "none", tol = 1e-9)

Visualize model on training data using metadata on cancer type

The get_metadata_colors() function returns an assignment of a color for the metadata columns. The nmb_get_gs() function returns the global scores from the input NipalsResult object.

meta_colors <- get_metadata_colors(mcia_results = MCIA_train, color_col = 1,
                                   color_pal_params = list(option = "E"))

global_scores <- nmb_get_gs(MCIA_train)
MCIA_out <- data.frame(global_scores[, 1:2])
MCIA_out$cancerType <- nmb_get_metadata(MCIA_train)$cancerType
colnames(MCIA_out) <- c("Factor.1", "Factor.2", "cancerType")

# plot the results
ggplot(data = MCIA_out, aes(x = Factor.1, y = Factor.2, color = cancerType)) +
  geom_point(size = 3) +
  labs(title = "MCIA for NCI60 training data") +
  scale_color_manual(values = meta_colors) +
  theme_bw()

Generate factor scores for test data using the MCIA_train model

We use the function to generate new factor scores on the test data set using the MCIA_train model. The new dataset in the form of an MAE object is input using the parameter test_data.

MCIA_test_scores <- predict_gs(mcia_results = MCIA_train,
                               test_data = data_blocks_test_mae)

Visualize new scores with old

We once again plot the top two factor scores for both the training and test datasets

MCIA_out_test <- data.frame(MCIA_test_scores[, 1:2])
MCIA_out_test$cancerType <-
  MultiAssayExperiment::colData(data_blocks_test_mae)$cancerType

colnames(MCIA_out_test) <- c("Factor.1", "Factor.2", "cancerType")
MCIA_out_test$set <- "test"
MCIA_out$set <- "train"
MCIA_out_full <- rbind(MCIA_out, MCIA_out_test)
rownames(MCIA_out_full) <- NULL

# plot the results
ggplot(data = MCIA_out_full,
       aes(x = Factor.1, y = Factor.2, color = cancerType, shape = set)) +
  geom_point(size = 3) +
  labs(title = "MCIA for NCI60 training and test data") +
  scale_color_manual(values = meta_colors) +
  theme_bw()

Session Info

Session Info

sessionInfo()
## R version 4.4.1 (2024-06-14)
## Platform: x86_64-pc-linux-gnu
## Running under: Ubuntu 22.04.4 LTS
## 
## Matrix products: default
## BLAS:   /home/biocbuild/bbs-3.19-bioc/R/lib/libRblas.so 
## LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.10.0
## 
## locale:
##  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
##  [3] LC_TIME=en_GB              LC_COLLATE=C              
##  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
##  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
##  [9] LC_ADDRESS=C               LC_TELEPHONE=C            
## [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
## 
## time zone: America/New_York
## tzcode source: system (glibc)
## 
## attached base packages:
## [1] stats4    grid      stats     graphics  grDevices utils     datasets 
## [8] methods   base     
## 
## other attached packages:
##  [1] MultiAssayExperiment_1.30.3 SummarizedExperiment_1.34.0
##  [3] Biobase_2.64.0              GenomicRanges_1.56.1       
##  [5] GenomeInfoDb_1.40.1         IRanges_2.38.1             
##  [7] S4Vectors_0.42.1            BiocGenerics_0.50.0        
##  [9] MatrixGenerics_1.16.0       matrixStats_1.3.0          
## [11] stringr_1.5.1               nipalsMCIA_1.2.1           
## [13] ggpubr_0.6.0                ggplot2_3.5.1              
## [15] fgsea_1.30.0                dplyr_1.1.4                
## [17] ComplexHeatmap_2.20.0       BiocStyle_2.32.1           
## 
## loaded via a namespace (and not attached):
##  [1] rlang_1.1.4             magrittr_2.0.3          clue_0.3-65            
##  [4] GetoptLong_1.0.5        compiler_4.4.1          png_0.1-8              
##  [7] vctrs_0.6.5             pkgconfig_2.0.3         shape_1.4.6.1          
## [10] crayon_1.5.3            fastmap_1.2.0           magick_2.8.4           
## [13] backports_1.5.0         XVector_0.44.0          labeling_0.4.3         
## [16] utf8_1.2.4              rmarkdown_2.28          pracma_2.4.4           
## [19] UCSC.utils_1.0.0        tinytex_0.52            purrr_1.0.2            
## [22] xfun_0.47               zlibbioc_1.50.0         cachem_1.1.0           
## [25] jsonlite_1.8.8          highr_0.11              DelayedArray_0.30.1    
## [28] BiocParallel_1.38.0     broom_1.0.6             parallel_4.4.1         
## [31] cluster_2.1.6           R6_2.5.1                bslib_0.8.0            
## [34] stringi_1.8.4           RColorBrewer_1.1-3      car_3.1-2              
## [37] jquerylib_0.1.4         Rcpp_1.0.13             bookdown_0.40          
## [40] iterators_1.0.14        knitr_1.48              BiocBaseUtils_1.6.0    
## [43] Matrix_1.7-0            tidyselect_1.2.1        abind_1.4-5            
## [46] yaml_2.3.10             doParallel_1.0.17       codetools_0.2-20       
## [49] lattice_0.22-6          tibble_3.2.1            withr_3.0.1            
## [52] evaluate_0.24.0         circlize_0.4.16         pillar_1.9.0           
## [55] BiocManager_1.30.25     carData_3.0-5           foreach_1.5.2          
## [58] generics_0.1.3          munsell_0.5.1           scales_1.3.0           
## [61] glue_1.7.0              tools_4.4.1             data.table_1.16.0      
## [64] RSpectra_0.16-2         ggsignif_0.6.4          Cairo_1.6-2            
## [67] fastmatch_1.1-4         cowplot_1.1.3           tidyr_1.3.1            
## [70] colorspace_2.1-1        GenomeInfoDbData_1.2.12 cli_3.6.3              
## [73] fansi_1.0.6             viridisLite_0.4.2       S4Arrays_1.4.1         
## [76] gtable_0.3.5            rstatix_0.7.2           sass_0.4.9             
## [79] digest_0.6.37           SparseArray_1.4.8       farver_2.1.2           
## [82] rjson_0.2.22            htmltools_0.5.8.1       lifecycle_1.0.4        
## [85] httr_1.4.7              GlobalOptions_0.1.2