---
title: "Using broadSeq to analyze RNA-seq data"
output: 
    BiocStyle::html_document:
        toc_float: true
vignette: >
  %\VignetteIndexEntry{Using broadSeq to analyze RNA-seq data}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

```{r setup, include = FALSE}
library(broadSeq)
```

# Introduction  

To analyze RNA-seq **count** data, there are several ways/methods for each steps
like

1.  Transforming/scaling of the count data,

2.  QC by clustering the samples using PCA, hierarchical clustering or 
multidimensional scaling

3.  Most importantly identification of differentially expressed.

For each of these steps, there are different packages or tools whose input and 
output formats are very different. Therefore it is very difficult to use all 
these features from different packages in a study.

```{r fig.cap = "Input and output data structures of different methods to idetify differentially expressed genes.", echo = FALSE}
knitr::include_graphics("img/io_p.png")
```

The *broadSeq* package simplifies the process of including many **Bioconductor** 
packages for RNA-seq data and evaluating their performance.

```{r echo = FALSE,fig.cap="Flowchart"}
knitr::include_graphics("img/broadSeq.png")
```

The silent features of *broadSeq* are

-   **Single input format** : `r Biocpkg("SummarizedExperiment")` 
-   **Single output format** : as base `data.frame`
-   Visualization : Using `ggplot2` and `ggpubr` packages for publication ready 
figures
-   Easy and advanced PCA analysis
-   Function oriented interface to include in existing pipeline.
-   Differential expression
    -   Comparison of different methods

# Reading the data

```{r eval = FALSE}
library(broadSeq)
library(ggplot2)
```

Here we read gene expression data which is quantified by `salmon` and
processed by `r Biocpkg("tximport")` package. The `salmon` generates count data,
"abundance" (TPM) and gene length values. Therefore we may rename the corresponding
assay slot 'abundance' to 'TPM'.

These data belongs to this studies reference!!

In this data, there are gene expression values from first molar tissue
of three different developing rodent species. The tissues are also from
four different developmental time points.

```{r message=FALSE}
se <- readRDS(system.file("extdata","rat_vole_mouseSE_salmon.rds", package = "broadSeq"))
SummarizedExperiment::assayNames(se)
```

## Sample metadata

```{r }
as.data.frame(colData(se)) %>% dplyr::count(stage,species) %>% tidyr::spread(stage,n)

se$stage <- factor(se$stage,levels = c("Bud","Cap","Late Cap","Bell"))
```

## Filtering out low expression genes

```{r lowExpr,warning=FALSE,fig.width= 6}
assays(se)[["counts"]][,5] %>% ggpubr::ggdensity(y = "count")+
    ggplot2::geom_vline(xintercept = 10)+ggplot2::scale_x_log10()

keep <- (assays(se)[["counts"]] >= 3) %>% rowSums() >= 5 
# smallest Group Size is 5
table(keep)
```

# Normalization

`r Biocpkg("edgeR")` provides two different methods ; CPM and TMM. But it does not use
normalized values for Differential Expression.

It also does not normalizes count values rather it normalizes the
library sizes using "TMM" method in 'normLibSizes'. Either use or not
use normLibSizes(). edgeR::cpm() will generate normalized expression
values.

## CPM

```{r warning=FALSE,message=FALSE}
se <- broadSeq::normalizeEdgerCPM(se ,method = "none",cpm.log = TRUE )
## The normalized values are added with the assay name "logCPM"
SummarizedExperiment::assayNames(se)
```

## TMM

```{r warning=FALSE,message=FALSE}
se <- broadSeq::normalizeEdgerCPM(se , method = "TMM", cpm.log = FALSE )
## The normalized values are added with the assay name "TMM"
SummarizedExperiment::assayNames(se)
```

## access

```{r }
assays(se)[["counts"]][1:5,1:5]
assays(se)[["TMM"]][1:5,1:5]
assays(se)[["logCPM"]][1:5,1:5]
```

# Transformation

`r Biocpkg("DESeq2")` provides three different transformations

## VST

variance stabilizing transformation (VST)

```{r warning=FALSE}
se <- broadSeq::transformDESeq2(se,method = "vst"  )
```

## Normalized counts transformation

```{r }
se <- broadSeq::transformDESeq2(se, method = "normTransform"  )
```

## rlog

regularized log

```{r eval=FALSE}
se <- broadSeq::transformDESeq2(se, method = "rlog")
```

```{r }
SummarizedExperiment::assayNames(se)
```

## Comparision

Boxplot of different transforms for each sample.

```{r warning=FALSE,fig.height=6,fig.width=8}
p <- broadSeq::sampleAssay_plot(se[, se$species=="Mouse" ], 
                           assayName = "counts", fill = "stage", 
                           yscale = "log2")+ rremove("x.text")

p1 <- broadSeq::sampleAssay_plot(se[, se$species=="Mouse"], 
                           assayName = "vst", fill = "stage")+ rremove("x.text")

p2 <- broadSeq::sampleAssay_plot(se[, se$species=="Mouse"], 
                           assayName = "TMM", fill = "stage", 
                           yscale = "log10")+ rremove("x.text")

p3 <- broadSeq::sampleAssay_plot(se[, se$species=="Mouse"], 
                           assayName = "logCPM", fill = "stage")+ rremove("x.text")


ggarrange(p,p1,p2,p3, common.legend = TRUE, labels = c("A","B","C"))
```

Plot standard deviations versus means expression

```{r eval=FALSE}
if (requireNamespace("vsn", quietly = TRUE)) {
    library("vsn")
    x <- meanSdPlot(
        log2(assays(se[, se$species == "Rat"])[["counts"]]+1),
        plot = FALSE)
    print(x$gg +ggtitle(label = "log2(n+1) "))
    
    x <- meanSdPlot(
        assays(se[, se$species == "Rat"])[["vst"]],
        plot = FALSE)
    
    print(x$gg +ggtitle(label = "Vst"))
    
    x <- meanSdPlot(
        assays(se[, se$species == "Rat"])[["logCPM"]],
        plot = FALSE)
    print(x$gg + ggtitle(label = "logCPM"))
}    

```

# Visualization of gene Expression

```{r message=FALSE,warning=FALSE}
## Multiple assay of a single gene
broadSeq::assay_plot(se, feature = c("Shh"), 
           assayNames = c("counts","logCPM","vst","TMM"),
           x = "stage", fill="species", add="dotplot", palette = "npg")

## Expression of multiple genes from a single assay
broadSeq::genes_plot(se, 
                     features = c("Shh","Edar"), 
                     facet.by = "symbol",
                     x = "stage", assayName = "vst", fill="species", palette = "jco")
```

## Pre-defined or custom color palette based on journals

Scientific journal palettes from `ggsci` R package, e.g.: "npg", "aaas",
"lancet", "jco", "ucscgb", "uchicago", "simpsons" and "rickandmorty" can
be passed for coloring or filling by groups from metadata.

```{r warning=FALSE,message=FALSE,fig.height=6,fig.width=8}
jco <- broadSeq::genes_plot(se[,se$species == "Mouse"], 
                     features = c("Shh"), facet.by = "symbol", assayName =  "logCPM",
                     x = "stage",  fill="stage", add="dotplot", xlab = "", 
                     title = "Journal of Clinical Oncology", palette = "jco") 

npg <- broadSeq::genes_plot(se[,se$species == "Mouse"], 
                     features = c("Shh"), facet.by = "symbol",assayName =  "logCPM",
                     x = "stage", fill="stage", add="dotplot", xlab = "",
                     title = "Nature Publishing Group", palette = "npg") 

aaas <- broadSeq::genes_plot(se[,se$species == "Mouse"], 
                     features = c("Shh"), facet.by = "symbol", assayName = "logCPM",
                     x = "stage", fill="stage", add="dotplot", xlab = "",
                     title = "Science", palette = "aaas")

nejm <- broadSeq::genes_plot(se[,se$species == "Mouse"], 
                     features = c("Shh"), facet.by = "symbol", assayName = "logCPM",
                     x = "stage", fill="stage", add="dotplot",  xlab = "",
                     title = "New England Journal of Medicine",palette = "nejm")

# ggarrange(jco,npg,aaas,nejm, 
#           common.legend = TRUE,legend = "none",
#           labels = c("A","B","C","D"))

ggarrange(jco+ggpubr::rotate_x_text(), npg+ggpubr::rotate_x_text(),
          aaas+ggpubr::rotate_x_text(),nejm+ggpubr::rotate_x_text(),
          nrow = 1, common.legend = TRUE,legend = "none",
          labels = c("A","B","C","D")) %>% 
    annotate_figure( top = text_grob("Color palette")) 
```

# QC with Clustering

## MDS plot

Classical multidimensional scaling is based on measuring the distance
between the samples.

Popular function plotMDS from `r Biocpkg("limma")` does not work with
`r Biocpkg("SummarizedExperiment")` object. Here broadSeq provides this function
through package `cmdscale {stats}`.

```{r fig.height=6,fig.width=8}
broadSeq::plot_MDS(se, scaledAssay = "vst", ntop=500, 
                   color = "species", shape = "stage", 
                   ellipse=TRUE, legend = "bottom")
```

MDS is cool but it is not possible to know/visualize top variable genes
with their meta data which is stored in `se` object

```{r }
head(rowData(se))
```

Other methods can help to visualize gene information along with
clustering information.

## Hierarchical clustering and Heatmap

```{r fig.height=6,fig.width=8}
p_vst <- broadSeq::plotHeatmapCluster(
    se,
    scaledAssay = "vst",
    annotation_col = c("species", "stage"),
    annotation_row = c("Class","gene_biotype"),
    ntop = 30, show_geneAs = "symbol",
    cluster_cols = TRUE, cluster_rows = FALSE,
    show_rownames = TRUE, show_colnames = FALSE,
    main = "Top 30 variable gene vst"
)
```

## PCA plot

### prcompTidy

Perform Principal Components Analysis with function
`broadSeq::prcompTidy()` which returns a list of four `data.frame`
objects:

-   pc_scores,

-   eigen_values,

-   loadings (eigen vectors) and

-   the original data.

    Compute PCA using any assay

```{r warning=FALSE}
computedPCA_logCPM <- broadSeq::prcompTidy(se, scaledAssay = "logCPM", ntop = 500)
## PCA based on vst values
computedPCA_vst <- broadSeq::prcompTidy(se, scaledAssay = "vst", ntop = 500)
```

### Plot

#### logCPM

```{r fig.width=8,fig.height=6}
plotAnyPC(computedPCA = computedPCA_logCPM,
          x = 1, y = 2, color = "species", shape = "stage",
          legend = "bottom")
```

#### VST

Here PC 2 and 3 are used which can cluster the samples by both species and developmental
factors. 
```{r fig.width=8,fig.height=6}
pca_vst <- plotAnyPC(computedPCA = computedPCA_vst,
            x = 2, y = 3,  color = "species", shape = "stage", 
            legend = "bottom") 
```

#### Other PCs

```{r fig.width=8,fig.height=6}
computedPCA_vst$eigen_values %>%
        dplyr::filter(var_exp >= 2) %>%
    ggbarplot(x="PC",y="var_exp", label = TRUE, label.pos = "out")
```

It can be checked if there are other PCs to explain considerable
variance. PC3 can be useful to see variance due to different
developmental time points.

```{r fig.width=8,fig.height=6}
pca_vst_2_3 <-plotAnyPC(computedPCA = computedPCA_vst,
                x = 2, y = 3,  
                color = "species", shape = "stage", legend = "bottom")
# pca_vst_2_3
```

PC3 captures beautifully the variance in gene expression due to
developmental stages.
<!-- The PCAs are different since the top 500 genes are different for rlog and vst.   -->

#### Gene loading

```{r fig.width=7,fig.height=6}
computedPCA_vst %>% broadSeq::getFeatureLoadRanking(keep = c("symbol","Class")) %>% head()

#  Top 5 genes of PC2

computedPCA_vst$loadings %>% top_n(5,abs(PC2)  ) %>% dplyr::select(gene,PC2)

pca_vst_loading <- computedPCA_vst %>% 
    broadSeq::getFeatureLoadRanking(keep = c("symbol","Class"), topN = 50, pcs=1:10) %>% 
    dplyr::count(Class, PC) %>%
    ggbarplot(
        x = "PC", y = "n", fill = "Class",
        legend = "bottom", palette = c("red","blue","orange","purple","white","grey")
    ) 
# pca_vst_loading
```

#### Biplot

```{r fig.width=8,fig.height=6}
# By default it plots top 2 genes from each PC axis
pca_vst_bi <- broadSeq::biplotAnyPC(computedPCA = computedPCA_vst, 
            x = 1, y = 2, genesLabel = "symbol", 
            color = "species", shape = "stage", 
            legend = "bottom")
# pca_vst_bi
```


```{r fig.width=8,fig.height=8}
ggarrange(
    ggarrange(pca_vst_bi+ggtitle(label =  ""),
          pca_vst_2_3+ggtitle(label =  ""), common.legend = TRUE),
    pca_vst_loading, nrow = 2)

```

#### User defined genes

Now plotting top 5 genes from PC3

```{r fig.width=8,fig.height=6}
# Top 5 genes of PC3
biplotAnyPC(computedPCA = computedPCA_vst,x = 2, y = 3, 
            color = "species", shape = "stage",
            genes= computedPCA_vst$loadings %>% 
                top_n(5,abs(PC3)) %>% pull(gene),
            genesLabel = "symbol")

## Plot progression gene "Shh" 
biplotAnyPC(computedPCA = computedPCA_vst,x = 2, y = 3, 
            color = "species", shape = "stage",
            genes=c("Shh"),
            genesLabel = "symbol")
```


# Compare Differential expression 

## Data 

In this example we will use RNA-seq expression data from developing mouse molar tissue. First we read the data as a `SummarizedExperiment` object. 

```{r warning=FALSE,eval=TRUE}
se <- readRDS(system.file("extdata","rat_vole_mouseSE_salmon.rds", package = "broadSeq"))

# To reduce the run time, subset of the data used here
se <- se[,colData(se)$species == "Mouse"]
```


```{r warning=FALSE,eval=FALSE,echo=FALSE}
count_matrix <- as.matrix(read.table(file = system.file("extdata", 
                                              "tooth_RNASeq_counts.txt", 
                                              package = "DELocal")))
colData <- data.frame(condition=gsub("\\..*",x=colnames(count_matrix),replacement = ""))

gene_location <- read.table(file = system.file("extdata", 
                                              "gene_location.txt", 
                                              package = "DELocal"))

se <- SummarizedExperiment::SummarizedExperiment(assays=list(counts=count_matrix),
                                                      rowData = gene_location, 
                                                      colData=colData)
# contrast= c("condition","ME13","ME14")
```

### Gene information

```{r warning=FALSE}
head(rownames(se))
head(rowData(se))
```

### Sample information  

The sample metadata  

```{r warning=FALSE,eval=TRUE}
head(colData(se))
table(colData(se)$stage)
```
<!-- There are two biological conditions ME13 and ME14 (embryonic days 13 and 14) with seven replicates each. The relevant question is which genes are differentially expressed between these two developmental time points. -->

## Differential Expression  

There are four developmental time points; Bud, Cap, Late Cap and Bell (from embryonic days 13 to 16) with seven replicates each. Here, in this example, DE genes between Bud and Cap stages will be identified.

### Function pattern  

In broadSeq, the names of DE method has similar pattern like "use_"+"method name". All these method has same signature of input arguments. 

Here we will see `use_NOIseq()` method to apply `NOISeq::noiseqbio()` function.   

```{r warning=FALSE,fig.width=6,fig.height=6,message=FALSE}
result_Noiseq <- 
    use_NOIseq(se = se, 
           colData_id = "stage", control = "Bud", treatment = "Cap",
           rank = TRUE, 
           r = 10) # r is an argument of NOISeq::noiseqbio

head(result_Noiseq)
```



```{r warning=FALSE,fig.width=8,fig.height=6,message=FALSE}
pg <- broadSeq::genes_plot(se, x = "stage", assayName =  "counts",  
           features = result_Noiseq %>% dplyr::filter(rank <5) %>% rownames(),
           fill="stage", facet.by = "symbol",
           palette="jco", add = "dotplot")+rotate_x_text()

pg_sc <- ggscatter(result_Noiseq, x="Bud_mean", y="Cap_mean",color = "prob")+ 
    scale_x_log10()+scale_y_log10()

pg+pg_sc
```

<!-- Note that the results="hide" and fig.keep = "none" parameters were added to the code chunk to prevent printing of the R code results and the exploratory plots created in the code chunk. -->

### Available methods

Following implementations of popular methods are available here.
```{r warning=FALSE,results="hide", fig.keep = "none"}
# limma 
?use_limma_trend(se, colData_id, control, treatment, rank = FALSE, ...)
?use_limma_voom(se, colData_id, control, treatment, rank = FALSE, ...)

# edgeR 
?use_edgeR_exact(se, colData_id, control, treatment, rank = FALSE, ...)
?use_edgeR_GLM(se, colData_id, control, treatment, rank = FALSE, ...)

# deseq2
?use_deseq2(se, colData_id, control, treatment, rank = FALSE, ...)

# DELocal
?use_DELocal(se, colData_id, control, treatment, rank = FALSE, ...)

# noiseq
?use_NOIseq(se, colData_id, control, treatment, rank = FALSE, ...) 

# EBSeq 
?use_EBSeq(se, colData_id, control, treatment, rank = FALSE, ...)

# samseq
?use_SAMseq(se, colData_id, control, treatment, rank = FALSE, ...)
```

Advanced users can pass package specific arguments through '...' .

## Compare DE results

It is possible to execute all DE methods together and get aggregated results in a data.frame.
`broadSeq::use_multDE()` should be used for it.

```{r warning=FALSE,results="hide", fig.keep = "none"}
# First define a named list of functions
funs <- list(limma_trend = use_limma_trend, limma_voom = use_limma_voom,
             edgeR_exact = use_edgeR_exact, edgeR_glm = use_edgeR_GLM,
             deseq2 = use_deseq2, 
             DELocal = use_DELocal, noiseq = use_NOIseq, 
             EBSeq = use_EBSeq) 


multi_result <- broadSeq::use_multDE(
    se = se, 
    deFun_list = funs, return.df = TRUE,  
    colData_id = "stage", control = "Bud", treatment = "Cap", 
    rank = TRUE)
```

The column names of the resultant data.frame are prefixed with corresponding function names. 

```{r warning=FALSE}
head(multi_result)
# nrow(multi_result) == nrow(se)
colnames(multi_result)
```

#### Similarity of methods

DE methods are clustered based on their ranking of genes

```{r warning=FALSE,fig.width=6,fig.height=6,eval=TRUE}
clusters <- multi_result %>% dplyr::select(ends_with("rank")) %>% t() %>% dist() %>% hclust()
plot(clusters,main =  "distance: Euclidean")
```

### Plots

#### Volcano 

Up regulated genes should be red or hot colors  

```{r warning=FALSE,fig.width=6,fig.height=6,eval=TRUE}
multi_result %>% broadSeq::volcanoPlot(
    pValName = "deseq2_padj",
    lFCName = "deseq2_log2FoldChange",
    labelName = "symbol",
    palette = "lancet" ,
    selectedLabel =
        multi_result %>% dplyr::arrange(deseq2_padj) %>% pull(symbol) %>% head()
)

multi_result %>% broadSeq::volcanoPlot(
    pValName = "deseq2_padj",
    lFCName = "deseq2_log2FoldChange",
    labelName = "symbol",
    palette = c("purple","orange","grey"),
    selectedLabel = list(criteria = "(`x` > 5 | `x` < -2) & (`y` > 10)")
) +xlim(-7.5,7.5)
```


<details>
<summary>Session Info</summary>

```{r warning=FALSE,error=FALSE}
sessionInfo()
```

</details>
