phylojs/lib/esm/io/writers/nexus.js

A simple typescript library for phylogenetic trees

import { newickRecurse } from './newick';
/** Writes tree in .nexus format. Undefined branch lengths set to 0.
 * @param {tree} tree The tree to write
 * @param {boolean} annotate Boolean to include annotations. Default is true.
 */
export function writeNexus(tree, annotationWriter = _annotation => '') {
    let nexusStr = '#NEXUS\n\nbegin trees;\n';
    if (tree.root !== undefined)
        nexusStr +=
            `\ttree tree_1 = [&R] ${newickRecurse(tree.root, annotationWriter)};` +
                '\n';
    nexusStr += 'end;';
    return nexusStr;
}