11 Replies Latest reply: Aug 3, 2017 6:49 PM by Rob Wunderlich

# Median value on x-axis

I have a bar chart (histogram, really) where the x-axis is a rounded number of hours (the delay in hours between admission to hospital and the start of surgery), and the y-axis is the number of cases.

Is there a way to show a vertical line at the median number of hours?

RoundedOpDelay is a dimension, calculated on data load.  However, I also have a separate numeric field called Delay(Hrs) to two decimal places if that works better.

Thanks,

Steve

• ###### Re: Median value on x-axis

you can try this Expression

median(TOTAL [Delay(Hrs)])

• ###### Re: Median value on x-axis

Thanks, Tim,

I have a KPI box that shows the median value as a number using your formula, and maybe I should be satisfied with that.  It would be really impressive, though, to have a different-coloured vertical line on the chart.

To chart this as a second dimension I would need something to use as a Y-axis number, probably matching the maximum number of operations per RoundedOpDelay (or the chart range).

Any suggestions?

Thanks again,

Steve

• ###### Re: Median value on x-axis

the screenshot is only an example

regards

tim

• ###### Re: Median value on x-axis

Thanks, Tim,

If you were to group your Total Sales into, say, \$500 blocks and chart them on the X-axis, you would be able to chart the number of times you hit each group of \$500.  Looking at your example, there would be a value of 1 for <\$500, 6 for \$1000, 3 for \$1500, 4 for \$2000, 0 for \$2500, 2 for \$3000, 0 for \$3500 and 1 for \$4000.  (Be patient here; I'm sitting with a ruler pressed on the screen and people are laughing at me.)

Your data doesn't readily lend itself to my histogram, but this is the sort of thing I'm hoping for:

The columns represent the \$500 groups; the value is a count of order dates, and the vertical red line represents the median order value.

On my bar chart at the top, the vertical red line would probably turn up at about 17 hours, as there's a long tail out to the right.

Steve

• ###### Re: Median value on x-axis

The Reference Line option for Bar Chart should be available under Add-ons, Reference Lines.

-Rob

http://qlikviewcookbook.com

• ###### Re: Median value on x-axis

Thanks Rob,

I can add the median value as a reference line, but it plots against the Y-axis as a horizontal line, rather than on the x axis, vertically.

Steve

• ###### Re: Median value on x-axis

Hadn't noticed that there is no X/Y option for the ref line (unlike that other product). What a disappointment.

You could color the bar closest to the median as a sort of workaround.

-Rob

• ###### Re: Median value on x-axis

Hi,

In case anybody is looking for this answer - seems unlikely - here's what I did:

I used color by expression, using this:

I had hoped to find the RGB value for the standard colors but in the end I used a color picker and found the closest I could.

Thanks for the suggestion, Rob.

Steve

• ###### Re: Median value on x-axis

To use a color from the standard palette, you can use the color(n) function. e.g. "color(2)" for the red color. These are slightly less saturated versions than the auto colors, but at least you get consistency.

-Rob

http://qlikviewcookbook.com

• ###### Re: Median value on x-axis

Thanks, Rob,

You'll have seen the peculiarities in June 2017's Colors / Custom / by Expression.  My original application had a map with the location of ambulance pick-up points by the type of injury event, where a car crash displayed a blue spot, motorcycle was cyan, fall was red, and so on for six trauma types.  It made a very interesting and informative map.  (This is a tiny illustration.)

All of the spots became grey with June 2017's release.

I found a post that explained that colours had to be enclosed in speech marks ('), and I've alternated these depending on the effect.

In case other people have this problem, your color(2) works without speech marks. Red() - a rich, deep colour - works without, but red (a dramatic crimson) needs them: 'red'.

In my map, both RGB and ARGB must be enclosed

but in a plain bar chart they don't:

I understand that this is a bug that will be fixed in an update, but in the meantime a little experimentation helps!

Steve

• ###### Re: Median value on x-axis

The map bug I'm not sure about. But I can explain the quote requirement on the bar chart.

RBG() and red() are both functions (note the parens) that must be evaluated, so they are unquoted.

'red' is a "color keyword" and it therefore quoted as literal string.

Interesting how many flavors or red we have now

-Rob