Method $setIndex

src/danfojs-base/core/generic.ts:276–290

* Internal function to set the index of the NDFrame with the specified * array of indices. Performs all necessary checks to ensure that the * index is valid.

(index: Array<string | number> | undefined)

     * index is valid.
    */
    $setIndex(index: Array<string | number> | undefined): void {
        if (index) {

            if (this.$data.length != 0 && index.length != this.shape[0]) {
                ErrorThrower.throwIndexLengthError(this, index)
            }
            if (Array.from(new Set(index)).length !== this.shape[0]) {
                ErrorThrower.throwIndexDuplicateError()
            }

            this.$index = index
        } else {
            this.$index = utils.range(0, this.shape[0] - 1) //generate index
        }
    }

    /**
     * Internal function to reset the index of the NDFrame using a range of indices.