Estoy tratando de usar los esquemas angulares que se muestran enesta página Cuando trato de usar el siguiente comando en la terminal en la raíz del proyectong generate @ angular / material: material-nav --name name-of-new-nav, Obtengo el siguiente error en rojo,

Collection "@ angular / material" no se puede resolver. Error: la colección "@ angular / material" no se puede resolver. en NodeModulesEngineHost._resolveCollectionPath (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular-devkit/schematics/tools/node-module-engine-host.js:88:15) atn. createCollectionDescription (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular-devkit/schematics/tools/file-system-engine-host-base.js:106:27) en SchematicEngine._CreateCol (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular-devkit/schematics/src/engine/engine.js:78:40) en SchematicEngine.createCollection (/ Users / jeremypeters / MEGA / MEGA /development/learning/angular/material-learn/node_modules/@angular-devkit/schematics/src/engine/engine.js:71:43) en Object.getCollection (/ Users / jeremypeters / MEGA / development / learning / angular / material-learn/node_modules/@angular/cli/utilities/schematics.js: 28: 31) en GenerateCommand.getOptions (/ Users / jeremypeters / MEGA / development / learning / angul ar/material-learn/node_modules/@angular/cli/models/schematic-command.js: 193: 41) en GenerateCommand. (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular/cli/commands/generate.js:38:53) en Generator.next () en / Users / jeremypeters / MEGA / development /learning/angular/material-learn/node_modules/@angular/cli/commands/generate.js:7:71 en new Promise ()

¿Cómo hago que esto funcione?

Info: CLI angular: 6.0.8