Summarize proximity scores

Computes the median or mean proximity score for each protein pair across all group combinations defined by group_vars. This is typically useful when profiling a population of interest, where the goal is to compute representative proximity scores for each protein pair within that population.

The proximity table typically contains a small fraction of the possible protein pairs for each cell. These missing pairs typically have UMI counts below the detection threshold and their proximity scores can therefore be imputed as 0 (0 observed join counts and 0 expected join counts => no deviation from the expected value). SummarizeProximityScores pads the proximity score vectors with 0s for the missing pairs to ensure that the summary statistics are computed for the entire population. This behavior can be turned off by setting include_missing_obs = FALSE.

Usage

SummarizeProximityScores(object, ...)

# S3 method for class 'tbl_lazy'
SummarizeProximityScores(
  object,
  proximity_metric = c("log2_ratio", "join_count_z"),
  group_vars = NULL,
  include_missing_obs = TRUE,
  summary_stat = c("mean", "median"),
  detailed = FALSE,
  ...
)

# S3 method for class 'data.frame'
SummarizeProximityScores(
  object,
  proximity_metric = "log2_ratio",
  group_vars = NULL,
  include_missing_obs = TRUE,
  summary_stat = c("mean", "median"),
  detailed = FALSE,
  ...
)

Arguments

object

A tbl_df or tbl_lazy object with proximity scores.

...

Additional arguments. Currently not used.

proximity_metric

The proximity metric to use. One of "log2_ratio" or "join_count_z".

group_vars

A character vector with the names of the variables to use for grouping This is typically used is you want to summarize the proximity scores for multiple cell types and/or conditions.

include_missing_obs

Logical indicating whether to include missing observations as 0 when computing the summary statistics.

summary_stat

One of "mean" or "median"

detailed

Logical indicating whether to return lists which can be used to compute custom summary statistics. See examples for details

Value

A tbl_df with summary statistics

Examples

library(pixelatorR)
library(dplyr)

pxl_file <- minimal_pna_pxl_file()
se <- ReadPNA_Seurat(pxl_file)
proximity_table <- ProximityScores(se)

# Default method uses mean
SummarizeProximityScores(proximity_table) %>% head()
#> # A tibble: 6 × 7
#>   marker_1 marker_2 n_cells_detected n_cells n_cells_missing pct_detected
#>   <chr>    <chr>               <int>   <int>           <int>        <dbl>
#> 1 CD56     CD71                    4       5               1          0.8
#> 2 CD56     CD59                    4       5               1          0.8
#> 3 CD56     CX3CR1                  4       5               1          0.8
#> 4 CD366    Siglec-9                5       5               0          1  
#> 5 CD366    CD79a                   5       5               0          1  
#> 6 CD366    GPR56                   4       5               1          0.8
#> # ℹ 1 more variable: mean_log2_ratio <dbl>

# Switch to median
SummarizeProximityScores(proximity_table, summary_stat = "median") %>% head()
#> # A tibble: 6 × 7
#>   marker_1 marker_2 n_cells_detected n_cells n_cells_missing pct_detected
#>   <chr>    <chr>               <int>   <int>           <int>        <dbl>
#> 1 CD56     mIgG1                   4       5               1          0.8
#> 2 CD366    NKp80                   5       5               0          1  
#> 3 CD366    HLA-DQ                  4       5               1          0.8
#> 4 CD366    CD54                    5       5               0          1  
#> 5 CD366    CD38                    5       5               0          1  
#> 6 CD366    CD90                    5       5               0          1  
#> # ℹ 1 more variable: median_log2_ratio <dbl>

# Ignore missing values
SummarizeProximityScores(proximity_table, include_missing_obs = FALSE) %>% head()
#> # A tibble: 6 × 7
#>   marker_1 marker_2 n_cells_detected n_cells n_cells_missing pct_detected
#>   <chr>    <chr>               <int>   <int>           <int>        <dbl>
#> 1 CD56     CD8                     4       5               1          0.8
#> 2 CD56     mIgG2a                  4       5               1          0.8
#> 3 CD56     CD94                    4       5               1          0.8
#> 4 CD56     VISTA                   4       5               1          0.8
#> 5 CD56     TCRVd2                  3       5               2          0.6
#> 6 CD366    CD93                    5       5               0          1  
#> # ℹ 1 more variable: mean_log2_ratio <dbl>

# Return lists which can be used to compute custom summary statistics
SummarizeProximityScores(proximity_table, detailed = TRUE) %>%
  # It's important to do rowwise computations
  rowwise() %>%
  mutate(
    sd = sd(unlist(log2_ratio_list)),
    iqr = IQR(unlist(log2_ratio_list)),
    mad = mad(unlist(log2_ratio_list)),
    q90 = quantile(unlist(log2_ratio_list), 0.9)
  ) %>%
  select(marker_1, marker_2, sd, iqr, mad, q90) %>%
  ungroup()
#> # A tibble: 12,561 × 6
#>    marker_1 marker_2     sd   iqr   mad   q90
#>    <chr>    <chr>     <dbl> <dbl> <dbl> <dbl>
#>  1 CD56     TCRgd    0          0     0 0    
#>  2 CD366    CD41     0          0     0 0    
#>  3 CD366    CD49D    0.783      0     0 0.407
#>  4 CD366    CD81     0.709      0     0 0.951
#>  5 CD366    CD369    0          0     0 0    
#>  6 CD366    CD64     0          0     0 0    
#>  7 CD366    TCRVg9   0          0     0 0    
#>  8 CD366    CD7      0.0731     0     0 0    
#>  9 CD366    CD66b    0          0     0 0    
#> 10 CD37     CD93     0.136      0     0 0.182
#> # ℹ 12,551 more rows