Clamp (function)

In computer science, clamping, or clipping is the process of limiting a value to a range between a minimum and a maximum value. Unlike wrapping, clamping merely moves the point to the nearest available value.

colspan="2" \| Y = clamp(X, 1, 3)
class="wikitable" style="margin:0 0 0 1em; text-align:right; float:right;"
X	Y
0	1
1	1
2	2
3	3
4	3

In Python, clamping can be defined as follows:

def clamp(x, minimum, maximum):

if x < minimum:

return minimum

if x > maximum:

return maximum

return x

This is equivalent to {{code |lang=python |max(minimum, min(x, maximum))}} for languages that support the functions min and max.

Uses

Several programming languages and libraries provide functions for fast and vectorized clamping. In Python, the pandas library offers the Series.clip{{cite web |url=https://pandas.pydata.org/docs/reference/api/pandas.Series.clip.html |title=Pandas Series.clip method documentation |access-date=2023-10-15}} and DataFrame.clip{{cite web |url=https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.clip.html |title=Pandas DataFrame.clip method documentation |access-date=2023-10-15}} methods. The NumPy library offers the clip{{cite web|url=https://numpy.org/doc/stable/reference/generated/numpy.clip.html |title=NumPy clip function documentation |access-date=2023-10-15}} function. In the Wolfram Language, it is implemented as {{code |lang=Mathematica |Clip[x, {minimum, maximum}]}}.{{cite web |url=https://reference.wolfram.com/language/ref/Clip.html |title=Wolfram Language Clip function documentation |access-date=2023-10-15}}

In OpenGL, the glClearColor function takes four GLfloat values which are then 'clamped' to the range $[0,1]$ .{{Cite web|url=https://www.khronos.org/registry/OpenGL-Refpages/gl4/|title=OpenGL 4 Reference Pages|website=www.khronos.org|access-date=2018-10-31}}

One of the many uses of clamping in computer graphics is the placing of a detail inside a polygon—for example, a bullet hole on a wall. It can also be used with wrapping to create a variety of effects.

In CSS, clamp(){{cite web |title=clamp() |url=https://developer.mozilla.org/en-US/docs/Web/CSS/clamp |website=MDN Web Docs |publisher=Mozilla}} can help to implement responsive typography or responsive designs generally.{{cite web |last1=Bece |first1=Adrian |title=Modern Fluid Typography Using CSS Clamp |url=https://www.smashingmagazine.com/2022/01/modern-fluid-typography-css-clamp/ |website=Smashing Magazine |publisher=Smashing Media AG |access-date=29 January 2025}}

Although spreadsheets like Excel, Open Office Calc, or Google Sheets don't provide a clamping function directly, the same effect can be achieved by using functions like MAX & MIN together, by MEDIAN,{{cite web |last1=Citi |first1=Jasper |title=How do I constrain a value to a range in excel? |url=https://stackoverflow.com/a/44716590/1024811 |website=Stack Overflow |access-date=29 January 2025}}{{cite web |title=Clamp function in Excel |url=https://www.excelforum.com/excel-general/781864-clamp-function-in-excel.html |website=Excel Forum |access-date=29 January 2025}} or with cell function macros.{{cite web |title=[Solved] Math Clamp Function? |url=https://forum.openoffice.org/en/forum/viewtopic.php?t=90037 |website=Apache OpenOffice Community Forum |access-date=29 January 2025}} When attempting to do a clamp where the input is an array, other methods must be used.{{cite web |title=Array-Safe Clamp Value in Google Sheets |url=https://webapps.stackexchange.com/questions/80921/array-safe-clamp-value-in-google-sheets |website=Stack Exchange > Web Applications |publisher=Stack Overflow |access-date=29 January 2025}}

References

Category:Computer graphics algorithms

Category:Articles with example Python (programming language) code