Repository: bacpop/ska.rust (rust)

Issue:
Add kmer count per sample to ska nk output
There is a really useful QC step with SKA which is to look at the total kmers for each sample. The total kmer numbers should be close to the genome size of the organism to indicate (1) good genome coverage (2) no contamination which will show more kmers, so it's always the first thing we check. 

It would be helpful to have that metric for each sample in the current `ska nk` summary output. 

Thanks for the new and more powerful implementation!

Pull request description:
Add k-mer counts per sample to ska nk; efficiency of dup counting
`ska nk` now looks like:
```
ska_version=0.2.2
k=21
k_bits=64
rc=true
k-mers=3228084
samples=28
sample_names=["19183_4#73", "12673_8#29", "12673_8#31", "12754_5#61", "12754_5#89", "12754_5#47", "12754_5#32", "12754_5#78", "12754_4#85", "12754_5#74", "19183_4#57", "12754_5#36", "19183_4#49", "19183_4#79", "19183_4#60", "12754_5#24", "12754_5#22", "12754_5#71", "12673_8#26", "12754_5#95", "12754_5#86", "12673_8#24", "19183_4#61", "12673_8#41", "12754_4#66", "12754_5#80", "12754_5#84", "19183_4#78"]
sample_kmers=[2872587, 2997448, 2949719, 2997496, 2997178, 2912749, 2996491, 2997221, 2949102, 2997454, 2914109, 2912237, 2872518, 2869957, 2872470, 2997992, 2997647, 2958512, 2998099, 2997290, 2950253, 3027707, 2997881, 2907920, 2911447, 2997644, 2944830, 2915080]
```

Also small change to how duplicates are counted which doesn't change any results but tidies the code a bit

Closes #39 

Patch:
diff --git a/Cargo.toml b/Cargo.toml
index 21f5442..d211c9c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ska"
-version = "0.3.0"
+version = "0.3.1"
 authors = [
     "John Lees <jlees@ebi.ac.uk>",
     "Simon Harris <simon.harris@gatesfoundation.org>",
@@ -12,7 +12,7 @@ authors = [
 edition = "2021"
 description = "Split k-mer analysis"
 repository = "https://github.com/bacpop/ska.rust/"
-homepage = "https://bacpop.com/software/"
+homepage = "https://bacpop.org/software/"
 license = "Apache-2.0"
 readme = "README.md"
 include = [
diff --git a/README.md b/README.md
index 0ffeab3..c0f4a69 100644
--- a/README.md
+++ b/README.md
@@ -51,12 +51,13 @@ Optimisations include:
 - Integer DNA encoding, optimised parsing from FASTA/FASTQ.
 - Faster dictionaries.
 - Full parallelisation of build phase.
-- Smaller, standardised input/output files.
+- Smaller, standardised input/output files. Faster to save/load.
 - Reduced memory footprint with read filtering.
 
 And other improvements:
 
-- IUPAC uncertainty codes for multiple copy k-mers.
+- IUPAC uncertainty codes for multiple copy split k-mers.
+- Uncertainty with self-reverse-complement split k-mers (palindromes).
 - Fully dynamic files (merge, delete samples).
 - Native VCF output for map.
 - Support for known strand sequence (e.g. RNA viruses).
diff --git a/src/lib.rs b/src/lib.rs
index 179418f..c0fb53d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -28,6 +28,11 @@
 //! Various optimisations are used to make this as fast as possible. For a more thorough comparison with version 1.0 of SKA, see the
 //! [github description](https://github.com/bacpop/ska.rust/blob/master/README.md).
 //!
+//! //! *NB As split k-mers are even lengths, it is possible that they are their
+//! own reverse complement. The original version of ska would randomly pick a strand,
+//! possibly introducing a SNP across samples. This version uses an ambiguous middle
+//! base (W for A/T; S for C/G) to represent this case.*
+//!
 //! Command line usage follows. For API documentation and usage, see the [end of this section](#api-usage).
 //!
 //! # Usage
@@ -228,20 +233,31 @@
 //! You can do this by removing any constant sites or ambiguous-only s0tes (which are typically unused), and by hard-filtering
 //! by frequency (i.e. before writing output):
 //! ```bash
-//! ska weed --filter NoAmbigOrConst --min-freq 0.9 all_samples.skf
+//! ska weed --filter no-ambig-or-const --min-freq 0.9 all_samples.skf
 //! ```
 //!
 //! ## ska nk
 //! Return information on the *n*umber of *k*-mers in an `.skf` file. This will
 //! print on STDOUT:
+//! - The version of ska used to build the file.
 //! - The k-mer size.
+//! - Number of bits used for the split k-mer (64 or 128).
 //! - Whether reverse complements were used.
-//! - The number of split k-mers.
-//! - The number of samples.
+//! - The total number of split k-mers.
+//! - The total number of samples.
 //! - The sample names.
+//! - The number of split k-mers found in each sample.
 //!
 //! ```bash
 //! ska nk all_samples.skf
+//! ska_version=0.3.1
+//! k=21
+//! k_bits=64
+//! rc=true
+//! k-mers=3228084
+//! samples=28
+//! sample_names=["19183_4#73", "12673_8#29", "12673_8#31", "12754_5#61", "12754_5#89", "12754_5#47", "12754_5#32", "12754_5#78", "12754_4#85", "12754_5#74", "19183_4#57", "12754_5#36", "19183_4#49", "19183_4#79", "19183_4#60", "12754_5#24", "12754_5#22", "12754_5#71", "12673_8#26", "12754_5#95", "12754_5#86", "12673_8#24", "19183_4#61", "12673_8#41", "12754_4#66", "12754_5#80", "12754_5#84", "19183_4#78"]
+//! sample_kmers=[2872587, 2997448, 2949719, 2997496, 2997178, 2912749, 2996491, 2997221, 2949102, 2997454, 2914109, 2912237, 2872518, 2869957, 2872470, 2997992, 2997647, 2958512, 2998099, 2997290, 2950253, 3027707, 2997881, 2907920, 2911447, 2997644, 2944830, 2915080]
 //! ```
 //!
 //! If you add `--full-info`, the split k-mer dictionary will be decoded and printed
diff --git a/src/merge_ska_array.rs b/src/merge_ska_array.rs
index c31feff..78f2115 100644
--- a/src/merge_ska_array.rs
+++ b/src/merge_ska_array.rs
@@ -416,6 +416,14 @@ where
             })
     }
 
+    /// Count of number of k-mers found in each sample
+    pub fn n_sample_kmers(&self) -> Vec<i32> {
+        self.variants
+            .map(|v| if *v != b'-' { 1 } else { 0 })
+            .sum_axis(Axis(0))
+            .to_vec()
+    }
+
     /// K-mer length used when builiding
     pub fn kmer_len(&self) -> usize {
         self.k
@@ -487,7 +495,7 @@ where
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(
             f,
-            "ska_version={}\nk={}\nk_bits={}\nrc={}\n{} k-mers\n{} samples\n",
+            "ska_version={}\nk={}\nk_bits={}\nrc={}\nk-mers={}\nsamples={}\n",
             self.ska_version,
             self.kmer_len(),
             self.k_bits,
@@ -495,7 +503,8 @@ where
             self.ksize(),
             self.nsamples()
         )?;
-        writeln!(f, "{:?}", self.names)
+        writeln!(f, "sample_names={:?}", self.names)?;
+        writeln!(f, "sample_kmers={:?}", self.n_sample_kmers())
     }
 }
 
diff --git a/src/ska_ref.rs b/src/ska_ref.rs
index b057cbd..9fae006 100644
--- a/src/ska_ref.rs
+++ b/src/ska_ref.rs
@@ -257,7 +257,11 @@ where
                     last_end = end;
                 }
             }
-            log::info!("Masking {} unique split k-mer repeats spanning {} bases", repeats.len(), repeat_coors.len());
+            log::info!(
+                "Masking {} unique split k-mer repeats spanning {} bases",
+                repeats.len(),
+                repeat_coors.len()
+            );
         }
 
         Self {
@@ -278,8 +282,7 @@ where
         if let Vacant(rep_kmer) = repeats.entry(kmer) {
             match singles.entry(kmer) {
                 Vacant(single_entry) => single_entry.insert(),
-                Occupied(single_entry) => {
-                    single_entry.remove();
+                Occupied(_) => {
                     rep_kmer.insert();
                 }
             }
@@ -383,7 +386,9 @@ where
         threads: usize,
     ) -> Result<(), needletail::errors::ParseError> {
         if self.chrom_names.len() > 1 {
-            log::warn!("Reference contained multiple contigs, in the output they will be concatenated");
+            log::warn!(
+                "Reference contained multiple contigs, in the output they will be concatenated"
+            );
         }
 
         let alignments = self.pseudoalignment(threads);


Test patch:
diff --git a/tests/test_results_correct/dup_ss_nk.stdout b/tests/test_results_correct/dup_ss_nk.stdout
index c62dd06..22863e4 100644
--- a/tests/test_results_correct/dup_ss_nk.stdout
+++ b/tests/test_results_correct/dup_ss_nk.stdout
@@ -2,9 +2,10 @@ ska_version=[..]
 k=9
 k_bits=64
 rc=false
-1 k-mers
-2 samples
-["dup_test_1", "dup_test_2"]
+k-mers=1
+samples=2
+sample_names=["dup_test_1", "dup_test_2"]
+sample_kmers=[1, 1]
 
 GATT	AAGG	K,D
 
diff --git a/tests/test_results_correct/k33.stdout b/tests/test_results_correct/k33.stdout
index a76cf25..1dbbfdd 100644
--- a/tests/test_results_correct/k33.stdout
+++ b/tests/test_results_correct/k33.stdout
@@ -2,7 +2,8 @@ ska_version=[..]
 k=33
 k_bits=128
 rc=true
-58 k-mers
-2 samples
-["test_1", "test_2"]
+k-mers=58
+samples=2
+sample_names=["test_1", "test_2"]
+sample_kmers=[30, 30]
 
diff --git a/tests/test_results_correct/merge_nk.stdout b/tests/test_results_correct/merge_nk.stdout
index 030c6a1..ad8854a 100644
--- a/tests/test_results_correct/merge_nk.stdout
+++ b/tests/test_results_correct/merge_nk.stdout
@@ -2,7 +2,8 @@ ska_version=[..]
 k=17
 k_bits=64
 rc=true
-78 k-mers
-2 samples
-["test_1", "test_2"]
+k-mers=78
+samples=2
+sample_names=["test_1", "test_2"]
+sample_kmers=[46, 46]
 
diff --git a/tests/test_results_correct/weed_nk.stdout b/tests/test_results_correct/weed_nk.stdout
index 5a60d34..fa397cd 100644
--- a/tests/test_results_correct/weed_nk.stdout
+++ b/tests/test_results_correct/weed_nk.stdout
@@ -2,9 +2,10 @@ ska_version=[..]
 k=17
 k_bits=64
 rc=true
-1 k-mers
-2 samples
-["test_1", "test_2"]
+k-mers=1
+samples=2
+sample_names=["test_1", "test_2"]
+sample_kmers=[1, 1]
 
 AAAACACT	TTAAAAGA	C,T
 
diff --git a/tests/test_results_correct/weed_nk_k41.stdout b/tests/test_results_correct/weed_nk_k41.stdout
index 703c8f1..9376b45 100644
--- a/tests/test_results_correct/weed_nk_k41.stdout
+++ b/tests/test_results_correct/weed_nk_k41.stdout
@@ -2,9 +2,10 @@ ska_version=[..]
 k=41
 k_bits=128
 rc=true
-1 k-mers
-2 samples
-["test_1", "test_2"]
+k-mers=1
+samples=2
+sample_names=["test_1", "test_2"]
+sample_kmers=[1, 1]
 
 AAAAGACTCTCGTACAGCTA	ATATCATAAACGCCTTCAAA	A,T