Charts (graphs) basics — add, title, type, reading back series/axes, delete

level: intermediate ／ verified: 2026-10-01 ／ tabs: Node.js・Python・Java・WebAssembly ／日本語

What you want to do

Create charts (graphs) from a data table on a worksheet. Build two kinds — a clustered column chart and a line chart — set their titles, legend and axes, and read the results back as properties to verify them. Finally, delete a chart.

A chart's appearance cannot be checked from the console, so this sample prints the type, title string, series values, axis settings and chart count with console.log, letting you programmatically confirm that everything was built as intended.

Classes involved

Charts are split into two layers: the "frame" (ChartObject) and the "content" (Chart).

Class	How to obtain	Role
`chart.ChartObject`	`ws.addChartObject(name, left, top, w, h)` / `ws.getChartObject(name\	index)`	Placement frame on the sheet. Position, size, name, visible/hidden
`chart.Chart`	`chartObject.getChart()`	The chart itself. Built with `chartWizard()`; handles type, data source, title, axes and series
`chart.ChartTitle`	`chart.getChartTitle()`	Chart title. `setText()` / `getText()`
`chart.Axis`	`chart.getAxes(enums.XlAxisType.Category\	Value)`	Axis. Tick marks, max/min, axis title
`chart.Series`	`chart.getSeriesCollection(index)`	One series. `getValues()` / `getXValues()` / `getPointSize()`
`chart.Legend`	`chart.getLegend()`	Legend. `setPosition()` / `getPosition()`

Chart-related methods on the WorkSheet side:

Method	Description
`addChartObject(name, left, top, width, height)`	Adds a chart frame. Position and size are in points (pt)
`getChartObject(name)` / `getChartObject(index)`	Gets by name or index (1-based). Out of range throws
`deleteChartObject(name)` / `deleteChartObject(index)`	Deletes by name or index

Code

Output:

// charts.js — charts (graphs) basics: add, title, type, reading back series/axes, delete
const { nodeosbxl, enums } = require("nodeosbxl");

const app = new nodeosbxl.App();
const wb = app.createWorkBook("charts.xlsx");
const ws = wb.openWorkSheet("Sheet1");

// Helper: chart type numeric code -> enum name
const chartTypeName = (code) =>
    Object.keys(enums.XlChartType).find((k) => enums.XlChartType[k] === code) || String(code);
// Helper: number of charts on the sheet (getChartObject throws out of range -> count until it does)
const countCharts = () => {
    let n = 0;
    for (;;) { try { ws.getChartObject(n + 1); n++; } catch (e) { break; } }
    return n;
};
// Helper: number of series in a chart (getSeriesCollection throws out of range)
const countSeries = (chart) => {
    let n = 0;
    for (;;) { try { chart.getSeriesCollection(n + 1); n++; } catch (e) { break; } }
    return n;
};

// ---------- 1. Build the data table (monthly sales of 2 products) ----------
["Month", "Product A", "Product B"].forEach((h, c) => ws.getCells(1, c + 1).setValue(h));
const sales = [
    ["Jan", 120, 90], ["Feb", 135, 95], ["Mar", 150, 110],
    ["Apr", 142, 125], ["May", 160, 118], ["Jun", 175, 130],
];
sales.forEach((row, i) => {
    ws.getCells(i + 2, 1).setValue(row[0]);
    ws.getCells(i + 2, 2).setNumberValue(row[1]);
    ws.getCells(i + 2, 3).setNumberValue(row[2]);
});
console.log("[1] Created data table A1:C7 / Product A total =",
    sales.reduce((s, r) => s + r[1], 0));

// ---------- 2. Add a clustered column chart (chartWizard) ----------
// addChartObject(name, left, top, width, height) — position and size are in points (pt)
const co1 = ws.addChartObject("SalesColumn", 320, 10, 360, 220);
const chart1 = co1.getChart();
// chartWizard(source, type, plotBy, seriesLabelLines, categoryLabelLines,
//             styleNo, colorNo, hasLegend, title)
chart1.chartWizard(
    "Sheet1!A1:C7",
    enums.XlChartType.ChartTypeColumnClustered,
    enums.XlRowCol.Columns,   // take series by column (Product A / Product B, one series each)
    1,                        // seriesLabelLines: first 1 row is the series-name header
    1,                        // categoryLabelLines: first 1 column is the category-name header
    1,                        // chartStyleNo (1-based)
    enums.XlChartColorPalette.XlPaletteColorful1,
    true,                     // hasLegend: show the legend
    "Monthly Sales"           // title: setting this displays the title
);
console.log("[2] type =", chartTypeName(chart1.getChartType()),
    "/ hasTitle =", chart1.hasTitle(),
    "/ title =", JSON.stringify(chart1.getChartTitle().getText()));
console.log("    data source =", chart1.getDataSource(),
    "/ plotBy =", chart1.getPlotBy(),
    "/ hasLegend =", chart1.hasLegend());

// ---------- 3. Read back series and axes ----------
// There is no API that returns the series name directly. Series names come from the
// chartWizard header row, so count them with getSeriesCollection and match each one
// to its header cell.
const n1 = countSeries(chart1);
console.log("[3] series count =", n1);
for (let i = 1; i <= n1; i++) {
    const s = chart1.getSeriesCollection(i);
    const name = Object.values(ws.getCells(1, i + 1).getValue())[0]; // series i -> header of column i+1
    console.log(`    series ${i} "${name}" values =`, JSON.stringify(s.getValues()),
        "/ point count =", s.getPointSize());
}
console.log("    category names =",
    JSON.stringify(chart1.getAxes(enums.XlAxisType.Category).getCategoryNames()));

// ---------- 4. Second chart (line with markers) + axis/legend settings ----------
const co2 = ws.addChartObject("SalesLine", 320, 250, 360, 220);
const chart2 = co2.getChart();
chart2.chartWizard(
    "Sheet1!A1:C7",
    enums.XlChartType.ChartTypeLineMarkers,
    enums.XlRowCol.Columns, 1, 1,
    1, enums.XlChartColorPalette.XlPaletteColorful1, true); // without hasLegend=true, getLegend() throws
// The title can also be set via setTitle(true) -> getChartTitle().setText()
chart2.setTitle(true);
chart2.getChartTitle().setText("Monthly Sales Trend");
// Value axis: fix max/min/major unit (read back with getMajorUnit and the ...IsAuto family)
const valAxis = chart2.getAxes(enums.XlAxisType.Value);
valAxis.setMaximumScale(200);
valAxis.setMinimumScale(0);
valAxis.setMajorUnit(50);
valAxis.setTitle(true);
valAxis.getTitle().setText("Sales (10K JPY)");
// Move the legend to the right
chart2.getLegend().setPosition(enums.XlLegendPosition.LegendPositionRight);

console.log("[4] type =", chartTypeName(chart2.getChartType()),
    "/ title =", JSON.stringify(chart2.getChartTitle().getText()));
console.log("    value axis major unit =", valAxis.getMajorUnit(),
    "/ max auto =", valAxis.getMaximumScaleIsAuto(),
    "/ min auto =", valAxis.getMinimumScaleIsAuto());
console.log("    value axis title =", JSON.stringify(valAxis.getTitle().getText()),
    "/ legend position =", chart2.getLegend().getPosition(),
    `(Right=${enums.XlLegendPosition.LegendPositionRight})`);

// ---------- 5. Read back chart count, position and size ----------
console.log("[5] chart count =", countCharts(),
    "/ SalesColumn(left,top,width,height) =",
    [co1.getLeft(), co1.getTop(), co1.getWidth(), co1.getHeight()].join(","));

// ---------- 6. Delete a chart ----------
ws.deleteChartObject("SalesLine");   // by name; deleteChartObject(2) by index (1-based) also works
console.log("[Done] Chart count after delete =", countCharts(),
    "/ remaining =", ws.getChartObject(1).getName());

wb.save();
wb.close();

# charts.py — charts (graphs) basics: same verification as the Node.js sample (pyosbxl)
import json
import pyosbxl

enums = pyosbxl.enums

app = pyosbxl.App()
wb = app.createWorkBook("charts-py.xlsx")
ws = wb.openWorkSheet("Sheet1")

# Helper: JSON-equivalent string (no separator spaces, non-ASCII kept as-is)
def jdump(v):
    return json.dumps(v, ensure_ascii=False, separators=(",", ":"))

# Helper: enum member name (pyosbxl enums expose their name via __name__)
def enum_name(v):
    return v.__name__

# Helper: number of charts on the sheet (getChartObject throws out of range -> count until it does)
def count_charts():
    n = 0
    while True:
        try:
            ws.getChartObject(n + 1)
            n += 1
        except Exception:
            return n

# Helper: number of series in a chart (getSeriesCollection throws out of range)
def count_series(chart):
    n = 0
    while True:
        try:
            chart.getSeriesCollection(n + 1)
            n += 1
        except Exception:
            return n

# ---------- 1. Build the data table (monthly sales of 2 products) ----------
for c, h in enumerate(["Month", "Product A", "Product B"]):
    ws.getCells(1, c + 1).setValue(h)
sales = [
    ["Jan", 120, 90], ["Feb", 135, 95], ["Mar", 150, 110],
    ["Apr", 142, 125], ["May", 160, 118], ["Jun", 175, 130],
]
for i, row in enumerate(sales):
    ws.getCells(i + 2, 1).setValue(row[0])
    ws.getCells(i + 2, 2).setNumberValue(row[1])
    ws.getCells(i + 2, 3).setNumberValue(row[2])
print("[1] Created data table A1:C7 / Product A total =", sum(r[1] for r in sales))

# ---------- 2. Add a clustered column chart (chartWizard) ----------
co1 = ws.addChartObject("SalesColumn", 320, 10, 360, 220)
chart1 = co1.getChart()
chart1.chartWizard(
    "Sheet1!A1:C7",
    enums.XlChartType.ChartTypeColumnClustered,
    enums.XlRowCol.Columns,   # take series by column (Product A / Product B, one series each)
    1,                        # seriesLabelLines: first 1 row is the series-name header
    1,                        # categoryLabelLines: first 1 column is the category-name header
    1,                        # chartStyleNo (1-based)
    enums.XlChartColorPalette.XlPaletteColorful1,
    True,                     # hasLegend: show the legend
    "Monthly Sales",          # title: setting this displays the title
)
print("[2] type =", enum_name(chart1.getChartType()),
      "/ hasTitle =", str(chart1.hasTitle()).lower(),
      "/ title =", jdump(chart1.getChartTitle().getText()))
print("    data source =", chart1.getDataSource(),
      "/ plotBy =", int(chart1.getPlotBy()),
      "/ hasLegend =", str(chart1.hasLegend()).lower())

# ---------- 3. Read back series and axes ----------
n1 = count_series(chart1)
print("[3] series count =", n1)
for i in range(1, n1 + 1):
    s = chart1.getSeriesCollection(i)
    name = list(ws.getCells(1, i + 1).getValue().values())[0]  # series i -> header of column i+1
    print(f'    series {i} "{name}" values =', jdump(s.getValues()),
          "/ point count =", s.getPointSize())
print("    category names =",
      jdump(chart1.getAxes(enums.XlAxisType.Category).getCategoryNames()))

# ---------- 4. Second chart (line with markers) + axis/legend settings ----------
co2 = ws.addChartObject("SalesLine", 320, 250, 360, 220)
chart2 = co2.getChart()
chart2.chartWizard(
    "Sheet1!A1:C7",
    enums.XlChartType.ChartTypeLineMarkers,
    enums.XlRowCol.Columns, 1, 1,
    1, enums.XlChartColorPalette.XlPaletteColorful1, True)  # without hasLegend=True, getLegend() throws
chart2.setTitle(True)
chart2.getChartTitle().setText("Monthly Sales Trend")
val_axis = chart2.getAxes(enums.XlAxisType.Value)
val_axis.setMaximumScale(200)
val_axis.setMinimumScale(0)
val_axis.setMajorUnit(50)
val_axis.setTitle(True)
val_axis.getTitle().setText("Sales (10K JPY)")
chart2.getLegend().setPosition(enums.XlLegendPosition.LegendPositionRight)

print("[4] type =", enum_name(chart2.getChartType()),
      "/ title =", jdump(chart2.getChartTitle().getText()))
print("    value axis major unit =", int(val_axis.getMajorUnit()),
      "/ max auto =", str(val_axis.getMaximumScaleIsAuto()).lower(),
      "/ min auto =", str(val_axis.getMinimumScaleIsAuto()).lower())
print("    value axis title =", jdump(val_axis.getTitle().getText()),
      "/ legend position =", int(chart2.getLegend().getPosition()),
      f"(Right={int(enums.XlLegendPosition.LegendPositionRight)})")

# ---------- 5. Read back chart count, position and size ----------
print("[5] chart count =", count_charts(),
      "/ SalesColumn(left,top,width,height) =",
      f"{int(co1.getLeft())},{int(co1.getTop())},{int(co1.getWidth())},{int(co1.getHeight())}")

# ---------- 6. Delete a chart ----------
ws.deleteChartObject("SalesLine")   # by name; deleteChartObject(2) by index (1-based) also works
print("[Done] Chart count after delete =", count_charts(),
      "/ remaining =", ws.getChartObject(1).getName())

wb.save()
wb.close()

// charts.java — charts (graphs) basics: same verification as the Node.js sample (javaosbxl)
import com.osboffice.osbxl.*;
import com.osboffice.osbxl.chart.*;
import com.osboffice.osbxl.enums.*;
import java.util.List;
import java.util.Map;

public class Main {
    // Helper: string list -> JSON-equivalent (["a","b"] form, same look as node's JSON.stringify)
    private static String jsonArr(List<String> list) {
        StringBuilder sb = new StringBuilder("[");
        for (int i = 0; i < list.size(); i++) {
            if (i > 0) sb.append(",");
            sb.append("\"").append(list.get(i)).append("\"");
        }
        return sb.append("]").toString();
    }

    // Helper: number of charts on the sheet (getChartObject throws out of range -> count until it does)
    private static int countCharts(WorkSheetWrapper ws) {
        int n = 0;
        while (true) {
            try { ws.getChartObject(n + 1); n++; } catch (Throwable t) { break; }
        }
        return n;
    }

    // Helper: number of series in a chart (getSeriesCollection throws out of range)
    private static int countSeries(ChartWrapper chart) {
        int n = 0;
        while (true) {
            try { chart.getSeriesCollection(n + 1); n++; } catch (Throwable t) { break; }
        }
        return n;
    }

    public static void main(String[] args) {
        AppWrapper app = new AppWrapper();
        WorkBookWrapper wb = app.createWorkBook("charts-java.xlsx");
        WorkSheetWrapper ws = wb.openWorkSheet("Sheet1");

        // ---------- 1. Build the data table (monthly sales of 2 products) ----------
        String[] headers = {"Month", "Product A", "Product B"};
        for (int c = 0; c < headers.length; c++) ws.getCells(1, c + 1).setValue(headers[c]);
        String[] months = {"Jan", "Feb", "Mar", "Apr", "May", "Jun"};
        int[] salesA = {120, 135, 150, 142, 160, 175};
        int[] salesB = {90, 95, 110, 125, 118, 130};
        int totalA = 0;
        for (int i = 0; i < months.length; i++) {
            ws.getCells(i + 2, 1).setValue(months[i]);
            ws.getCells(i + 2, 2).setNumberValue(salesA[i]);
            ws.getCells(i + 2, 3).setNumberValue(salesB[i]);
            totalA += salesA[i];
        }
        System.out.println("[1] Created data table A1:C7 / Product A total = " + totalA);

        // ---------- 2. Add a clustered column chart (chartWizard) ----------
        ChartObjectWrapper co1 = ws.addChartObject("SalesColumn", 320, 10, 360, 220);
        ChartWrapper chart1 = co1.getChart();
        chart1.chartWizard(
            "Sheet1!A1:C7",
            XlChartType.ChartTypeColumnClustered,
            XlRowCol.Columns,   // take series by column (Product A / Product B, one series each)
            1,                  // seriesLabelLines: first 1 row is the series-name header
            1,                  // categoryLabelLines: first 1 column is the category-name header
            1,                  // chartStyleNo (1-based)
            XlChartColorPalette.XlPaletteColorful1,
            true,               // hasLegend: show the legend
            "Monthly Sales");   // title: setting this displays the title
        System.out.println("[2] type = " + chart1.getChartType().name()
            + " / hasTitle = " + chart1.hasTitle()
            + " / title = \"" + chart1.getChartTitle().getText() + "\"");
        System.out.println("    data source = " + chart1.getDataSource()
            + " / plotBy = " + chart1.getPlotBy().getCode()   // enums are numeric via getCode()
            + " / hasLegend = " + chart1.hasLegend());

        // ---------- 3. Read back series and axes ----------
        int n1 = countSeries(chart1);
        System.out.println("[3] series count = " + n1);
        for (int i = 1; i <= n1; i++) {
            SeriesWrapper s = chart1.getSeriesCollection(i);
            Map<String, String> h = ws.getCells(1, i + 1).getValue();
            String name = h.values().iterator().next();       // series i -> header of column i+1
            System.out.println("    series " + i + " \"" + name + "\" values = " + jsonArr(s.getValues())
                + " / point count = " + s.getPointSize());
        }
        System.out.println("    category names = "
            + jsonArr(chart1.getAxes(XlAxisType.Category).getCategoryNames()));

        // ---------- 4. Second chart (line with markers) + axis/legend settings ----------
        ChartObjectWrapper co2 = ws.addChartObject("SalesLine", 320, 250, 360, 220);
        ChartWrapper chart2 = co2.getChart();
        chart2.chartWizard("Sheet1!A1:C7",
            XlChartType.ChartTypeLineMarkers,
            XlRowCol.Columns, 1, 1,
            1, XlChartColorPalette.XlPaletteColorful1, true); // without hasLegend=true, getLegend() throws
        chart2.setTitle(true);
        chart2.getChartTitle().setText("Monthly Sales Trend");
        AxisWrapper valAxis = chart2.getAxes(XlAxisType.Value);
        valAxis.setMaximumScale(200);
        valAxis.setMinimumScale(0);
        valAxis.setMajorUnit(50);
        valAxis.setTitle(true);
        valAxis.getTitle().setText("Sales (10K JPY)");
        chart2.getLegend().setPosition(XlLegendPosition.LegendPositionRight);

        System.out.println("[4] type = " + chart2.getChartType().name()
            + " / title = \"" + chart2.getChartTitle().getText() + "\"");
        System.out.println("    value axis major unit = " + (int) valAxis.getMajorUnit()   // double -> int for display
            + " / max auto = " + valAxis.getMaximumScaleIsAuto()
            + " / min auto = " + valAxis.getMinimumScaleIsAuto());
        System.out.println("    value axis title = \"" + valAxis.getTitle().getText() + "\""
            + " / legend position = " + chart2.getLegend().getPosition().getCode()
            + " (Right=" + XlLegendPosition.LegendPositionRight.getCode() + ")");

        // ---------- 5. Read back chart count, position and size ----------
        System.out.println("[5] chart count = " + countCharts(ws)
            + " / SalesColumn(left,top,width,height) = "
            + (int) co1.getLeft() + "," + (int) co1.getTop() + ","
            + (int) co1.getWidth() + "," + (int) co1.getHeight());

        // ---------- 6. Delete a chart ----------
        ws.deleteChartObject("SalesLine");   // by name; deleteChartObject(2) by index (1-based) also works
        System.out.println("[Done] Chart count after delete = " + countCharts(ws)
            + " / remaining = " + ws.getChartObject(1).getName());

        wb.save();
        wb.close();
    }
}

// charts.wasm.js — charts (graphs) basics: same verification as the Node.js sample (wasmosbxl / embind)
// Note (WebAssembly build): load the module first with createOsbxl(createModule).
// osbxl / dto / chart / enums used below are the four namespaces it returns
// (the equivalent of require("nodeosbxl") in the Node.js build).
const app = new osbxl.App();
const wb = app.createWorkBook("charts-wasm.xlsx");
const ws = wb.openWorkSheet("Sheet1");

// Helper: chart type numeric code -> enum name
const chartTypeName = (code) =>
    Object.keys(enums.XlChartType).find((k) => enums.XlChartType[k] === code) || String(code);
// Helper: number of charts on the sheet (getChartObject throws out of range -> count until it does)
const countCharts = () => {
    let n = 0;
    for (;;) { try { ws.getChartObject(n + 1); n++; } catch (e) { break; } }
    return n;
};
// Helper: number of series in a chart (getSeriesCollection throws out of range)
const countSeries = (chart) => {
    let n = 0;
    for (;;) { try { chart.getSeriesCollection(n + 1); n++; } catch (e) { break; } }
    return n;
};

// ---------- 1. Build the data table (monthly sales of 2 products) ----------
["Month", "Product A", "Product B"].forEach((h, c) => ws.getCells(1, c + 1).setValue(h));
const sales = [
    ["Jan", 120, 90], ["Feb", 135, 95], ["Mar", 150, 110],
    ["Apr", 142, 125], ["May", 160, 118], ["Jun", 175, 130],
];
sales.forEach((row, i) => {
    ws.getCells(i + 2, 1).setValue(row[0]);
    ws.getCells(i + 2, 2).setNumberValue(row[1]);
    ws.getCells(i + 2, 3).setNumberValue(row[2]);
});
console.log("[1] Created data table A1:C7 / Product A total =",
    sales.reduce((s, r) => s + r[1], 0));

// ---------- 2. Add a clustered column chart (chartWizard) ----------
const co1 = ws.addChartObject("SalesColumn", 320, 10, 360, 220);
const chart1 = co1.getChart();
chart1.chartWizard(
    "Sheet1!A1:C7",
    enums.XlChartType.ChartTypeColumnClustered,
    enums.XlRowCol.Columns,   // take series by column (Product A / Product B, one series each)
    1,                        // seriesLabelLines: first 1 row is the series-name header
    1,                        // categoryLabelLines: first 1 column is the category-name header
    1,                        // chartStyleNo (1-based)
    enums.XlChartColorPalette.XlPaletteColorful1,
    true,                     // hasLegend: show the legend
    "Monthly Sales"           // title: setting this displays the title
);
console.log("[2] type =", chartTypeName(chart1.getChartType()),
    "/ hasTitle =", chart1.hasTitle(),
    "/ title =", JSON.stringify(chart1.getChartTitle().getText()));
console.log("    data source =", chart1.getDataSource(),
    "/ plotBy =", chart1.getPlotBy(),
    "/ hasLegend =", chart1.hasLegend());

// ---------- 3. Read back series and axes ----------
const n1 = countSeries(chart1);
console.log("[3] series count =", n1);
for (let i = 1; i <= n1; i++) {
    const s = chart1.getSeriesCollection(i);
    const name = Object.values(ws.getCells(1, i + 1).getValue())[0]; // series i -> header of column i+1
    console.log(`    series ${i} "${name}" values =`, JSON.stringify(s.getValues()),
        "/ point count =", s.getPointSize());
}
console.log("    category names =",
    JSON.stringify(chart1.getAxes(enums.XlAxisType.Category).getCategoryNames()));

// ---------- 4. Second chart (line with markers) + axis/legend settings ----------
const co2 = ws.addChartObject("SalesLine", 320, 250, 360, 220);
const chart2 = co2.getChart();
chart2.chartWizard(
    "Sheet1!A1:C7",
    enums.XlChartType.ChartTypeLineMarkers,
    enums.XlRowCol.Columns, 1, 1,
    1, enums.XlChartColorPalette.XlPaletteColorful1, true); // without hasLegend=true, getLegend() throws
chart2.setTitle(true);
chart2.getChartTitle().setText("Monthly Sales Trend");
const valAxis = chart2.getAxes(enums.XlAxisType.Value);
valAxis.setMaximumScale(200);
valAxis.setMinimumScale(0);
valAxis.setMajorUnit(50);
valAxis.setTitle(true);
valAxis.getTitle().setText("Sales (10K JPY)");
chart2.getLegend().setPosition(enums.XlLegendPosition.LegendPositionRight);

console.log("[4] type =", chartTypeName(chart2.getChartType()),
    "/ title =", JSON.stringify(chart2.getChartTitle().getText()));
console.log("    value axis major unit =", valAxis.getMajorUnit(),
    "/ max auto =", valAxis.getMaximumScaleIsAuto(),
    "/ min auto =", valAxis.getMinimumScaleIsAuto());
console.log("    value axis title =", JSON.stringify(valAxis.getTitle().getText()),
    "/ legend position =", chart2.getLegend().getPosition(),
    `(Right=${enums.XlLegendPosition.LegendPositionRight})`);

// ---------- 5. Read back chart count, position and size ----------
console.log("[5] chart count =", countCharts(),
    "/ SalesColumn(left,top,width,height) =",
    [co1.getLeft(), co1.getTop(), co1.getWidth(), co1.getHeight()].join(","));

// ---------- 6. Delete a chart ----------
ws.deleteChartObject("SalesLine");   // by name; deleteChartObject(2) by index (1-based) also works
console.log("[Done] Chart count after delete =", countCharts(),
    "/ remaining =", ws.getChartObject(1).getName());

wb.save();
wb.close();

[1] Created data table A1:C7 / Product A total = 882
[2] type = ChartTypeColumnClustered / hasTitle = true / title = "Monthly Sales"
    data source = Sheet1!$A$1:$C$7 / plotBy = 2 / hasLegend = true
[3] series count = 2
    series 1 "Product A" values = ["120","135","150","142","160","175"] / point count = 6
    series 2 "Product B" values = ["90","95","110","125","118","130"] / point count = 6
    category names = ["Jan","Feb","Mar","Apr","May","Jun"]
[4] type = ChartTypeLineMarkers / title = "Monthly Sales Trend"
    value axis major unit = 50 / max auto = false / min auto = false
    value axis title = "Sales (10K JPY)" / legend position = 4 (Right=4)
[5] chart count = 2 / SalesColumn(left,top,width,height) = 320,10,360,220
[Done] Chart count after delete = 1 / remaining = SalesColumn

Notes

Creation is a two-step process: build the frame with addChartObject(), then the content with getChart().chartWizard(). addChartObject(name, left, top, width, height) only returns the placement frame (ChartObject); at that point the chart is not built yet. Only after calling chartWizard() on the Chart obtained via chartObject.getChart() are the type and data set.
Position and size are in points (pt).
The argument order of chartWizard() differs from Excel macros — be careful. The signature is chartWizard(source, chartType, plotBy, seriesLabelLines, categoryLabelLines, styleNo?, colorNo?, hasLegend?, title?, ...). source is an A1C1-style string like "Sheet1!A1:C7", seriesLabelLines=1 means "the first row holds series names" and categoryLabelLines=1 means "the first column holds category names".
plotBy is "which direction series are taken from". In a table like the one above — months in rows, products in columns (B/C) — passing enums.XlRowCol.Columns(=2) gives one series per column (Product A, Product B); the sample confirms 2 series.
The title can be set in two ways. Either pass a string as the title argument of chartWizard() (which makes hasTitle() return true), or call chart.setTitle(true) → chart.getChartTitle().setText("..."). Both can be read back with getChartTitle().getText().
Axes are obtained with getAxes(enums.XlAxisType.Category|Value). Set the value axis max/min with setMaximumScale() / setMinimumScale() and the tick interval with setMajorUnit(). The axis title is axis.setTitle(true) → axis.getTitle().setText().
Series values can be read back with getSeriesCollection(i).getValues() / getXValues() (both string arrays). There is no API that returns the series count itself, so the sample counts until getSeriesCollection() throws.

Caveats