Visx

Question 1

Domain

Answer 1

The set of possible output values, which are shown on the y-axis

Generally this is the Min and Max values in the data

Question 2

Range

Answer 2

all the input values shown on the y-axis

Generally this is 0 to width of the graph

Question 3

D3 Scale

Answer 3

A function which accepts input within the domain and maps it to output within the range.

You can use the function to calculate positions based on the data:
Domain: 0-10
Range: 0-600

myScale(0);   // returns 0
myScale(2);   // returns 120
myScale(3);   // returns 180
...
myScale(10);  // returns 600

Question 4

What are scale functions used for?

Answer 4

Scales are mainly used for transforming data values to visual variables such as position, length and colour

Question 5

Linear scale

Answer 5

Linear scale functions are typically used to transform data values into positions and lengths. They are useful when creating bar charts, line charts and many other chart types.
the range can also be specified as colours:

Question 6

Square Root scale

Answer 6

creates a square-root based scale. It transforms its domain in such a way that if the value b is 4 times bigger than value a, the result is only multiplied by 2.

Its most common use case is to determine the radius of a disk whose surface area must be proportional to the value (useful for sizing circles by area)

Question 7

Band scale

Answer 7

Band scales are like ordinal scales except the output range is continuous and numeric. Discrete output values are automatically computed by the scale by dividing the continuous range into uniform bands. Band scales are typically used for bar charts with an ordinal or categorical dimension

Question 8

Log scale

Answer 8

creates a logarithmic scale, a continuous scale in which the domain is transformed by the Math.log function

a log scale domain must be strictly-positive or strictly-negative; the domain must not include or cross zero.

Question 9

Radial scale

Answer 9

Radial scales are a variant of linear scales where the range is internally squared so that an input value corresponds linearly to the squared output value. These scales are useful when you want the input value to correspond to the area of a graphical mark and the mark is specified by radius, as in a radial bar chart

Question 10

Ordinal scale

Answer 10

ordinal scales have a discrete domain and range

Question 11

Point scale

Answer 11

Point scales are a variant of band scales with the bandwidth fixed to zero. Point scales are typically used for scatterplots with an ordinal or categorical dimension

Question 12

Power scale

Answer 12

creates a power based scale.

The transform applied to values is of the type y = x^k where k, the exponent, can be any real number.

Question 13

Time scale

Answer 13

Time scales are commonly used for charts where one axis represents the time or date. Line charts, bar charts, you name it. If a dimension of the data is expressed as Date objects, you will probably use d3.scaleTime instead of d3.scaleLinear to represent it on screen

The default domain is one full day, the 1st of January, 2000, in the local time zone (as set in the user’s environment, for example their browser).

Question 14

axis component

Answer 14

consists of a line with ticks, tick labels, and an axis label that helps viewers interpret your graph.

Question 15

what are the 5 different Axis components?

Question 16

@visx/curve package

Answer 16

functions that can be passed to other visx components to change the way the line is drawn

Question 17

@visx/grid package

Answer 17

lets you create gridlines for charts