logarithmic scale misses information about basis

20.xx The chart:major-origin attribute specifies the location of one major tick.

20.xx The chart:minor-logarithmic attribute specifies whether the minor ticks are spaced equally after the logarithmic transformation. If this value is false they are spaced equally before the transformation.

20.27 The chart:interval-major attribute specifies major intervals on an axis 11.8.
If the axis is linear and the value of this attribute is x with the value of chart:major-origin being w, major ticks are placed at w+n*x for n being any (positive, negative or zero) integer.
If the axis is logarithmic and the value of this attribute is x with the value of chart:major-origin being w, major ticks are placed at w*(10^(n*x)) for n being any (positive, negative or zero) integer. (Note: if

x = log_{10}(y)

, then

10^(n*x) = y^n

.)

20.28 The chart:interval-minor-divisor attribute specifies a divisor for the chart:interval-major value, the division of which determines the minor interval:

If chart:minor-logarithmic is false the ticks are placed as follows:
If a and b are the values of consecutive major ticks (see 20.27) and m is the value of chart:interval-minor-divisor then the minor ticks are placed at locations corresponding to the values a + (b-a)/m * k with k = 1,2, ..., (m-1). So the minor ticks are equally spaced before the logarithmic transformation.

If chart:minor-logarithmic is true the ticks are placed as follows:
If a and b are the values of consecutive major ticks (see 20.27) and m is the value of chart:interval-minor-divisor then the minor ticks are placed at locations corresponding to the values a*((b/a)^(k/m)) with k = 1,2, ..., (m-1). So the minor ticks are equally spaced after the logarithmic transformation.

Schema Change:

--- OpenDocument-v1.2-os-schema.rng	2017-10-27 18:22:13.973894000 -0600
+++ OpenDocument-v1.2-os-schema+log-changes.rng	2017-10-29 12:12:35.544258788 -0600
@@ -17476,11 +17476,21 @@
 				</attribute>
 			</optional>
 			<optional>
+				<attribute name="chart:major-origin">
+					<ref name="double"/>
+				</attribute>
+			</optional>
+			<optional>
 				<attribute name="chart:interval-major">
 					<ref name="double"/>
 				</attribute>
 			</optional>
 			<optional>
+				<attribute name="chart:minor-logarithmic">
+					<ref name="boolean"/>
+				</attribute>
+			</optional>
+			<optional>
 				<attribute name="chart:interval-minor-divisor">
 					<ref name="positiveInteger"/>
 				</attribute>

Resolve as proposed. 2 November 2020:

20.28 chart:interval-major

The chart:interval-major attribute specifies major intervals on an axis 11.9.

If the axis is linear and the value of this attribute is x with the value of chart:major-origin being w, major ticks are placed at w + n * x for n being any (positive, negative or zero) integer.

If the axis is logarithmic and the value of this attribute is x with the value of chart:major-origin being w, major ticks are placed at w * (10 ^{(n * x)}) for n being any (positive, negative or zero) integer.

Note: if x = log ₁₀ (y), then 10 ^{(n * x)} = y ⁿ.

This attribute is evaluated for a chart style that is applied to a <chart:axis> 11.9 element.

20.29 chart:interval-minor-divisor

The chart:interval-minor-divisor attribute specifies a divisor for the chart:interval-major 20.28 value, the division of which determines the minor interval.

If chart:minor-logarithmic attribute is false the ticks are placed as follows:

If a and b are the values of consecutive major ticks (see 20.28) and m is the value of chart:interval-minor-divisor then the minor ticks are placed at locations corresponding to the values a + (b - a) / m * k with k = 1,2, ... ,(m - 1). So the minor ticks are equally spaced before the logarithmic transformation.

If chart:minor-logarithmic attribute is true the ticks are placed as follows:

If a and b are the values of consecutive major ticks (see 20.28) and m is the value of chart:interval-minor-divisor then the minor ticks are placed at locations corresponding to the values a * ( (b / a) ^{(k / m)} ) with k = 1,2, ... ,(m - 1). So the minor ticks are equally spaced after the logarithmic transformation.

This attribute is evaluated for a chart style that is applied to a <chart:axis> 11.9 element.

20.37 chart:major-origin

The chart:major-origin attribute specifies the location of one major tick.

20.38 chart:minor-logarithmic

The chart:minor-logarithmic attribute specifies whether the minor ticks are spaced equally after the logarithmic transformation. If this value is false they are spaced equally before the transformation.