d3.js - Error: Invalid value for <rect> attribute width="NaN" -

i'm new d3. ive have completed quite few charts , examples "interactive data visualization web" scott murray , had few problems. first attempt @ using large data-set not contained within code.

d3.csv("historical_weather.csv", function(error,data) {

    dataset = data.map(function(d){          return [ parseint(+d.cloudcover),parseint(+ d.maxtemp) ];     })      console.log(dataset);       var svg = d3.select("body")         .append("svg")         .attr("height",500)         .attr("width",500);      d3.select("svg")         .selectall("rect")         .data("dataset")         .enter()         .append("rect")         .attr("height",50)         .attr("width", function(d){return d.maxtemp*10;});  }); 

the data loads , visible in console array, can see expected values when digging array. console shows :

error: invalid value attribute width="nan"

seems have typo. line says .data("dataset") should instead .data(dataset) no quotation marks. i.e., should submitting dataset variable, not string containing its' name.