JavaScript d3 passing arguments into a function that references d3.event.y

Question

I want to edit the dragmove function to accept arguments. This is the original code: ``` var drag = d3.behavior.drag() .on("drag", dragmove) .on("dragend", function(d){console.log("dragend"); }); focus.selectAll("circle") .data([coordinatesForecastCurrentMonth]) .enter() .append("circle") .attr("cx", function(d) { return x(d[0]);}) .attr("cy", function(d) { return y(d[1]);}) .attr("r", function(d) { return 5;}) .attr("clip-path", "url(#clip)") .call(drag); function dragmove(d) { d3.select(this) .attr("cy", d3.event.y);} ``` When I change it to the following: ``` .on("drag", dragmove(1,2)) function dragmove(arg1,arg2) { d3.select(this) .attr("cy", d3.event.y); console.log(arg1); console.log(arg2);} ``` I get this error: I don't understand why the event object cannot be found, can anyone help?

Accepted Answer

You are calling the function in your change instead of passing a reference to it. That is, you're calling it when the code is executed, not on drag. Hence, there's no `d3.event`. Make it a function reference like this.

```
.on("drag", function() { dragmove(1,2); });
```

The rest of the code can remain unchanged.

JavaScript d3 passing arguments into a function that references d3.event.y

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