Credit: BoredPanda Theyâre called HB rings and theyâre created by TheTouch. The minimalist designs are made from stainless steel and thereâs also a solid ros... Skip navigation
Contour lines normally connect areas with equal data values, so may generally be called isolines or isopleths-lines of the same value. Normally, the primary set of contour lines is displayed as a solid line, while the secondary contour is displayed as a &shed line. For example, a standard 850-hPa, 24-hour prognosis chart has height contours in solid lines, temperature contours in dashed lines, and wind speed and direction as plotted data.
More generally, a contour line for a function of two variables is a curve connecting points where the function has the same particular value. The gradient of the function is always perpendicular to the contour lines. When the lines are close together the magnitude of the gradient is large: the variation is steep. A level set is a generalization of a contour line for functions of any number of variables.