Added a count column on the histogram command (#1853)

* Adding iniitial draft for the addition of the count column on the histogram command

* Update histogram documentation

* Add count column test to histogram command

* Fix error in histogram documentation

crates/nu-cli/src/commands/histogram.rs

@@ -107,6 +107,32 @@ pub fn histogram(
 
                 let column = (*column_name).clone();
 
+                let count_column_name = "count".to_string();
+                let count_shell_error = ShellError::labeled_error("Unable to load group count", "unabled to load group count", &name);
+                let mut count_values: Vec<u64> = Vec::new();
+
+                for table_entry in reduced.table_entries() {
+                    match table_entry {
+                        Value {
+                            value: UntaggedValue::Table(list),
+                            ..
+                        } => {
+                            for i in list {
+                                if let Ok(count) = i.value.clone().into_value(&name).as_u64() {
+                                    count_values.push(count);
+                                } else {
+                                    yield Err(count_shell_error);
+                                    return;
+                                }
+                            }
+                        }
+                        _ => {
+                            yield Err(count_shell_error);
+                            return;
+                        }
+                    }
+                }
+
                 if let Value { value: UntaggedValue::Table(start), .. } = datasets.get(0).ok_or_else(|| ShellError::labeled_error("Unable to load dataset", "unabled to load dataset", &name))? {
                     for percentage in start.iter() {
 
@@ -114,6 +140,8 @@ pub fn histogram(
                         let value: Tagged<String> = group_labels.get(idx).ok_or_else(|| ShellError::labeled_error("Unable to load group labels", "unabled to load group labels", &name))?.clone();
                         fact.insert_value(&column, UntaggedValue::string(value.item).into_value(value.tag));
 
+                        fact.insert_untagged(&count_column_name, UntaggedValue::int(count_values[idx]));
+
                         if let Value { value: UntaggedValue::Primitive(Primitive::Int(ref num)), ref tag } = percentage.clone() {
                             let string = std::iter::repeat("*").take(num.to_i32().ok_or_else(|| ShellError::labeled_error("Expected a number", "expected a number", tag))? as usize).collect::<String>();
                             fact.insert_untagged(&frequency_column_name, UntaggedValue::string(string));

crates/nu-cli/tests/commands/histogram.rs

@@ -62,3 +62,22 @@ fn help() {
         assert_eq!(help_long.out, help_command.out);
     })
 }
+
+#[test]
+fn count() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+            echo "[{"bit":1},{"bit":0},{"bit":0},{"bit":0},{"bit":0},{"bit":0},{"bit":0},{"bit":1}]"
+            | from json
+            | histogram bit
+            | sort-by count
+            | reject frequency
+            | to json
+        "#
+    ));
+
+    let bit_json = r#"[{"bit":"1","count":2},{"bit":"0","count":6}]"#;
+
+    assert_eq!(actual.out, bit_json);
+}

docs/commands/histogram.md

@@ -17,64 +17,76 @@ Let's say we have this file `random_numers.csv` which contains 50 random numbers
 
 ```shell
 > open random_numbers.csv
-open random_numbers2.csv
+────┬────────────────
-━━━━┯━━━━━━━━━━━━━━━━
  #  │ random numbers
 ────┼────────────────
-  0 │ 0
+  0 │              1
-  1 │ 5
+  1 │              2
-  2 │ 5
+  2 │              2
         ...
- 47 │ 0
+ 47 │              5
- 48 │ 2
+ 48 │              5
- 49 │ 4
+ 49 │              1
-━━━━┷━━━━━━━━━━━━━━━━
+────┴────────────────
 ```
 
 If we now want to see how often the different numbers were generated, we can use the `histogram` function:
 
 ```shell
-> open random_numbers2.csv | histogram "random numbers"
+> open random_numbers.csv | histogram "random numbers"
-━━━┯━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+───┬────────────────┬───────┬──────────────────────────────────────────────────────────────────────────────────────────────────────
- # │ random numbers │ frequency
+ # │ random numbers │ count │ frequency
-───┼────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────
+───┼────────────────┼───────┼──────────────────────────────────────────────────────────────────────────────────────────────────────
- 0 │ 0              │ ****************************************************************************************************
+ 0 │ 0              │     1 │ ******
- 1 │ 1              │ ******************************
+ 1 │ 1              │    15 │ ****************************************************************************************************
- 2 │ 2              │ *************************************************************
+ 2 │ 2              │    10 │ ******************************************************************
- 3 │ 3              │ *********************************************************************
+ 3 │ 3              │     7 │ **********************************************
- 4 │ 4              │ *****************************************************
+ 4 │ 4              │     9 │ ************************************************************
- 5 │ 5              │ *********************************************************************
+ 5 │ 5              │     8 │ *****************************************************
-━━━┷━━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+───┴────────────────┴───────┴──────────────────────────────────────────────────────────────────────────────────────────────────────
 ```
 
 We can also set the name of the second column or sort the table:
 
 ```shell
-> open random_numbers2.csv | histogram "random numbers" probability
+> open random_numbers.csv | histogram "random numbers" probability
-━━━┯━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+───┬────────────────┬───────┬──────────────────────────────────────────────────────────────────────────────────────────────────────
- # │ random numbers │ probability
+ # │ random numbers │ count │ probability
-───┼────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────
+───┼────────────────┼───────┼──────────────────────────────────────────────────────────────────────────────────────────────────────
- 0 │ 0              │ ****************************************************************************************************
+ 0 │ 0              │     1 │ ******
- 1 │ 1              │ ******************************
+ 1 │ 1              │    15 │ ****************************************************************************************************
- 2 │ 2              │ *************************************************************
+ 2 │ 2              │    10 │ ******************************************************************
- 3 │ 3              │ *********************************************************************
+ 3 │ 3              │     7 │ **********************************************
- 4 │ 4              │ *****************************************************
+ 4 │ 4              │     9 │ ************************************************************
- 5 │ 5              │ *********************************************************************
+ 5 │ 5              │     8 │ *****************************************************
-━━━┷━━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+───┴────────────────┴───────┴──────────────────────────────────────────────────────────────────────────────────────────────────────
 
 ```
 
 ```shell
-> open random_numbers2.csv | histogram "random numbers" probability | sort-by probability
+> open random_numbers.csv | histogram "random numbers" probability | sort-by probability
-━━━┯━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+───┬────────────────┬───────┬──────────────────────────────────────────────────────────────────────────────────────────────────────
- # │ random numbers │ probability
+ # │ random numbers │ count │ probability
-───┼────────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────
+───┼────────────────┼───────┼──────────────────────────────────────────────────────────────────────────────────────────────────────
- 0 │ 1              │ ******************************
+ 0 │ 0              │     1 │ ******
- 1 │ 4              │ *****************************************************
+ 1 │ 3              │     7 │ **********************************************
- 2 │ 2              │ *************************************************************
+ 2 │ 5              │     8 │ *****************************************************
- 3 │ 3              │ *********************************************************************
+ 3 │ 4              │     9 │ ************************************************************
- 4 │ 5              │ *********************************************************************
+ 4 │ 2              │    10 │ ******************************************************************
- 5 │ 0              │ ****************************************************************************************************
+ 5 │ 1              │    15 │ ****************************************************************************************************
-━━━┷━━━━━━━━━━━━━━━━┷━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+───┴────────────────┴───────┴──────────────────────────────────────────────────────────────────────────────────────────────────────
 
 ```
+
+Of course, histogram operations are not restricted to just analyzing numbers in files, you can also analyze your directories
+
+```shell
+> ls -fa | histogram type | sort-by count
+───┬─────────┬───────┬──────────────────────────────────────────────────────────────────────────────────────────────────────
+ # │ type    │ count │ frequency
+───┼─────────┼───────┼──────────────────────────────────────────────────────────────────────────────────────────────────────
+ 0 │ Symlink │     8 │ *****************
+ 1 │ File    │     9 │ ********************
+ 2 │ Dir     │    45 │ ****************************************************************************************************
+───┴─────────┴───────┴──────────────────────────────────────────────────────────────────────────────────────────────────────
+```