diff --git a/README.md b/README.md
index 937fd14..e7961af 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ However, with some Reflection magic it is possible to do without this. This is w
Here is an example:
```groovy
-@Grab('se.alipsa.groovy:data-utils:1.0.0')
+@Grab('se.alipsa.groovy:data-utils:1.0.2')
@Grab('org.postgresql:postgresql:42.4.0')
import se.alipsa.groovy.datautil.SqlUtil
@@ -31,7 +31,7 @@ data-utils is available from maven central
Groovy:
```groovy
-implementation "se.alipsa.groovy:data-utils:1.0.1"
+implementation "se.alipsa.groovy:data-utils:1.0.2"
```
Maven:
@@ -39,12 +39,15 @@ Maven:
se.alipsa.groovy
data-utils
- 1.0.1
+ 1.0.2
```
## Version history
+### 1.0.2, 2022-08-17
+- Add TableUtil with support for frequency tables
+
### 1.0.1, 2022-07-25
- Upgrade to Groovy 4.0.4
- Build script fixes
diff --git a/build.gradle b/build.gradle
index b1c457b..388b696 100644
--- a/build.gradle
+++ b/build.gradle
@@ -13,14 +13,17 @@ repositories {
dependencies {
def groovyVersion = "[4.0.4, )"
+ def tablesawVersion = "[0.43.1, )"
implementation "org.apache.groovy:groovy:${groovyVersion}"
implementation "org.apache.groovy:groovy-sql:${groovyVersion}"
+ implementation "tech.tablesaw:tablesaw-core:${tablesawVersion}"
testImplementation 'org.junit.jupiter:junit-jupiter:5.8.2'
testImplementation 'com.h2database:h2:2.1.214'
+ testImplementation "org.slf4j:slf4j-simple:1.7.36"
}
group = 'se.alipsa.groovy'
-version = '1.0.1'
+version = '1.0.2'
description = 'Java FX GUI for Groovy based data science analysis and applications'
java.sourceCompatibility = JavaVersion.VERSION_17
diff --git a/src/main/groovy/se/alipsa/groovy/datautil/TableUtil.groovy b/src/main/groovy/se/alipsa/groovy/datautil/TableUtil.groovy
new file mode 100644
index 0000000..85f6122
--- /dev/null
+++ b/src/main/groovy/se/alipsa/groovy/datautil/TableUtil.groovy
@@ -0,0 +1,45 @@
+package se.alipsa.groovy.datautil
+
+import tech.tablesaw.api.ColumnType
+import tech.tablesaw.api.Row
+import tech.tablesaw.api.Table
+import tech.tablesaw.columns.Column
+
+import java.math.RoundingMode
+import java.util.concurrent.atomic.AtomicInteger
+
+class TableUtil {
+
+ static Table frequency(Column column) {
+ Map freq = new HashMap<>()
+ column.forEach(v -> {
+ freq.computeIfAbsent(v, k -> new AtomicInteger(0)).incrementAndGet()
+ });
+ int size = column.size()
+ def table = Table.create(column.name())
+ def valueCol = ColumnType.STRING.create("Value")
+ def freqCol = ColumnType.INTEGER.create("Frequency")
+ def percentCol = ColumnType.DOUBLE.create("Percent")
+ table.addColumns(valueCol, freqCol, percentCol)
+ for (Map.Entry entry : freq.entrySet()) {
+ Row row = table.appendRow()
+ row.setString("Value", String.valueOf(entry.getKey()))
+ int numOccurrence = entry.getValue().intValue()
+ row.setInt("Frequency", numOccurrence)
+ row.setDouble("Percent", round(numOccurrence * 100.0 / size, 2))
+ }
+ return table.sortDescendingOn("Frequency")
+ }
+
+ static Table frequency(Table table, String columnName) {
+ return frequency(table.column(columnName))
+ }
+
+ static double round(double value, int numDecimals) {
+ if (numDecimals < 0) throw new IllegalArgumentException("numDecimals cannot be a negative number: was " + numDecimals)
+
+ BigDecimal bd = BigDecimal.valueOf(value)
+ bd = bd.setScale(numDecimals, RoundingMode.HALF_UP)
+ return bd.doubleValue()
+ }
+}
diff --git a/src/test/groovy/test/alipsa/groovy/datautil/TableUtilTest.groovy b/src/test/groovy/test/alipsa/groovy/datautil/TableUtilTest.groovy
new file mode 100644
index 0000000..ace795b
--- /dev/null
+++ b/src/test/groovy/test/alipsa/groovy/datautil/TableUtilTest.groovy
@@ -0,0 +1,26 @@
+package test.alipsa.groovy.datautil
+
+import org.junit.jupiter.api.Assertions
+import se.alipsa.groovy.datautil.TableUtil;
+
+import static tech.tablesaw.api.ColumnType.*
+
+import org.junit.jupiter.api.Test
+import tech.tablesaw.api.*
+import tech.tablesaw.io.csv.CsvReadOptions
+
+public class TableUtilTest {
+
+ @Test
+ void testFrequency() {
+ def csv = getClass().getResource("/glaciers.csv")
+ CsvReadOptions.Builder builder = CsvReadOptions.builder(csv)
+ .separator(',' as Character)
+ .columnTypes([INTEGER, DOUBLE, INTEGER] as ColumnType[])
+
+ def glaciers = Table.read().usingOptions(builder.build())
+ def freq = TableUtil.frequency(glaciers, "Number of observations")
+ Assertions.assertEquals(20, freq.size())
+ Assertions.assertEquals(31, freq.get(0, 1))
+ }
+}
diff --git a/src/test/resources/glaciers.csv b/src/test/resources/glaciers.csv
new file mode 100644
index 0000000..386ec13
--- /dev/null
+++ b/src/test/resources/glaciers.csv
@@ -0,0 +1,71 @@
+Year,Mean cumulative mass balance,Number of observations
+1945,0,
+1946,-1.13,1
+1947,-3.19,1
+1948,-3.19,1
+1949,-3.82,3
+1950,-4.887,3
+1951,-5.217,3
+1952,-5.707,3
+1953,-6.341,7
+1954,-6.825,6
+1955,-6.575,7
+1956,-6.814,7
+1957,-6.989,9
+1958,-7.693,9
+1959,-8.325,11
+1960,-8.688,14
+1961,-8.935,15
+1962,-9.109,20
+1963,-9.567,22
+1964,-9.699,22
+1965,-9.298,24
+1966,-9.436,27
+1967,-9.303,29
+1968,-9.219,31
+1969,-9.732,31
+1970,-10.128,32
+1971,-10.288,32
+1972,-10.441,32
+1973,-10.538,32
+1974,-10.613,32
+1975,-10.534,33
+1976,-10.633,35
+1977,-10.682,37
+1978,-10.754,37
+1979,-11.127,37
+1980,-11.318,36
+1981,-11.394,35
+1982,-11.849,36
+1983,-11.846,37
+1984,-11.902,37
+1985,-12.238,37
+1986,-12.782,37
+1987,-12.795,37
+1988,-13.26,37
+1989,-13.343,37
+1990,-13.687,37
+1991,-14.255,37
+1992,-14.501,36
+1993,-14.695,37
+1994,-15.276,37
+1995,-15.486,37
+1996,-15.89,37
+1997,-16.487,37
+1998,-17.31,37
+1999,-17.697,37
+2000,-17.727,37
+2001,-18.032,37
+2002,-18.726,37
+2003,-19.984,37
+2004,-20.703,37
+2005,-21.405,37
+2006,-22.595,37
+2007,-23.255,37
+2008,-23.776,37
+2009,-24.459,37
+2010,-25.158,37
+2011,-26.294,37
+2012,-26.93,36
+2013,-27.817,31
+2014,-28.652,24